Tackified And Non-Tackified Nonwovens Of Controlled Stiffness And Retained Foldability

ABSTRACT

The present disclosure relates generally to a nonwoven filtration media comprising a bonded mix of different, discontinuous, thermoplastic resin fibers and optionally discontinuous cellulosic fibers. In some embodiments a tackifier is added to the nonwoven filtration media to provide a sticky or adhesive surface on the fibers. The nonwoven media has an advantageous combination of stiffness, foldability, efficiency and the ability to retain a fold. The nonwoven media can be thermally bonded during the production process. The advantageous combination of mechanical properties allow the disclosed nonwoven media to accept and retain folds and pleats better than some conventional filtration materials while the mix of different fibers provides desirable filtration properties.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of International Application No. PCT/FI2007/050281, filed May 16, 2007, which claims the benefit of U.S. Provisional Application No. 60/866,820, filed Nov. 21, 2006 and from U.S. Provisional Application No. 60/800,613, filed May 16, 2006, the contents of each of which are incorporated herein by reference in their entirety.

FIELD

The present disclosure relates generally to a nonwoven web comprising a mix of discontinuous, thermoplastic resin fibers having a combination of high stiffness, foldability and filtration properties. In some embodiments the fibers of the web are coated with a tackifier. The nonwoven web can advantageously be used as a filtration media. The present disclosure also provides a method of making the filtration media. In some embodiments the nonwoven filtration media can advantageously be used as part of an air filter.

BACKGROUND

Some desirable filtration properties of nonwoven fabrics used as filtration media are that they be permeable to the fluid being filtered yet have high filtration efficiency. High permeability to the fluid being filtered is desirable as less energy is required to move the fluid through the filter media. High filtration efficiency is, of course, desirable as it allows the filtration media to more effectively remove contaminants in the fluid being filtered. Filtration properties can be quantified using tests such as Frazier Permeability, dP, PFE efficiency and Index.

In many applications, filtration media are required which have structural integrity by themselves for conversion into various shapes. For example, the filtration media can be folded into a pleated shape that gives far more surface area than a non-pleated shape in the same space.

Large fibers in a filtration media provide stiffness for pleating but undesirably degrade filtration efficiency. Further, some stiff filtration media are difficult to fold and may not “hold” the pleat, allowing the pleat to close and degrading filtration properties. Small fibers in a filtration media improve efficiency and foldability but reduce stiffness. A filtration media having an advantageous combination of stiffness, foldability, filtration properties and the ability to retain a fold is desirable.

SUMMARY

The present disclosure relates generally to a nonwoven filtration media comprising a bonded mix of different, discontinuous, thermoplastic resin fibers and optionally discontinuous cellulosic fibers. The nonwoven media has an advantageous combination of Gurley Stiffness and LED score foldability within a preselected range dependent on the Gurley Stiffness, filtration properties and the ability to retain a fold. The nonwoven filtration media can be thermally bonded during the production process. The advantageous combination of high stiffness and foldability properties allow the disclosed nonwoven media to accept and retain folds and pleats better than some conventional filtration materials while the mix of different fibers provides desirable filtration properties.

One embodiment of the nonwoven filtration media comprising a bonded mix of different, discontinuous, thermoplastic resin fibers and optionally discontinuous cellulosic fibers. The nonwoven filtration media can be thermally bonded during the production process. At least some of the fibers are coated with a tackiness agent. The tackified, nonwoven media has an advantageous combination of Gurley Stiffness, an LED score foldability within a preselected range dependent on the Gurley Stiffness, filtration properties and the ability to retain a fold. The advantageous combination of high stiffness and foldability properties allow the disclosed nonwoven media to accept and retain folds and pleats better than some conventional filtration materials while the tackiness agent and mix of different fibers provides desirable filtration properties.

One embodiment of a nonwoven filtration media comprises a mix of 0 percent to about 90 percent of staple length fibers having a denier of 10 or greater and about 10 percent to about 100 percent of the fibers having a denier of 4 or less. About 30 percent to about 85 percent of the fibers will be conjugate fibers. Preferably, the nonwoven filtration media will comprise a mixture of 0 percent to about 85 percent conjugate fibers having a denier of 15 or more and 0 percent to about 80 percent of conjugate fibers having a denier of 4 or less. The staple length fibers are carded and cross lapped to form a single layer with the different fibers homogeneously distributed through the thickness of the layer. The nonwoven filtration media is thermally bonded by contact with heated rollers. This nonwoven filtration media will have a basis weight between about 90 gsm to about 370 gsm, a Frazier Permeability between about 150 CFM/square foot/square foot and about 850 CFM/square foot, a PFE greater than or equal to 30 percent, a dP between about 0.03 inches water gauge at 110 fpm and about 0.22 inches water gauge at 110 fpm, an Index between about 300 and about 1600, a MD Gurley stiffness of more than 1400 and an LED score foldability within a preselected range dependent on the Gurley Stiffness

One embodiment of a nonwoven filtration media comprises a mix of staple length fibers all having a denier of 5 or less. Advantageously, about 30 percent to about 85 percent of the fibers in the nonwoven filtration media will be conjugate fibers having a denier of 5 or less. The staple length fibers are carded and cross lapped to form a single layer with the different fibers homogeneously distributed through the thickness of the layer. The nonwoven filtration media is thermally bonded by contact with heated rollers. This nonwoven filtration media will have a basis weight between about 90 gsm to about 370 gsm, a Frazier Permeability between about 150 CFM/square foot and about 850 CFM/square foot, a PFE greater than or equal to 30 percent, a dP between about 0.03 inches water gauge at 110 fpm and about 0.22 inches water gauge at 110 fpm, an Index between about 300 and about 1600 a MD Gurley stiffness of more than 1400 and an LED score foldability within a preselected range dependent on the Gurley Stiffness

The disclosed nonwoven filtration media may be used in a number of different applications. The media is advantageously used in air filtration for home or commercial heating, ventilating and air conditioning (HVAC) services. It may also be used in filtration of breathing air in transportation applications like automobile cabin air filtration, airplane cabin air filtration, and train and boat air filtration. While the nonwoven filtration media is preferably directed to air filtration, in different embodiments other gasses and other fluids may be filtered as well. Such other gasses may include, for example, nitrogen. Other fluids may include liquids like oil or water.

In general, unless otherwise explicitly stated the disclosed materials and processes may be alternately formulated to comprise, consist of, or consist essentially of, any appropriate components, moieties or steps herein disclosed. The disclosed materials and processes may additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any components, materials, ingredients, adjuvants, moieties, species and steps used in the prior art compositions or that are otherwise not necessary to the achievement of the function and/or objective of the present disclosure.

When the word “about” is used herein it is meant that the amount or condition it modifies can vary some beyond the stated amount so long as the function and/or objective of the disclosure are realized. The skilled artisan understands that there is seldom time to fully explore the extent of any area and expects that the disclosed result might extend, at least somewhat, beyond one or more of the disclosed limits. Later, having the benefit of this disclosure and understanding the concept and embodiments disclosed herein, a person of ordinary skill can, without inventive effort, explore beyond the disclosed limits and, when embodiments are found to be without any unexpected characteristics, those embodiments are within the meaning of the term about as used herein.

DEFINITIONS

Biconstituent fiber—A fiber that has been formed from a mixture of two or more polymers extruded from the same spinneret. Biconstituent fibers do not have the various polymer components arranged in relatively constantly positioned distinct zones across the cross-sectional area of the fiber and the various polymers are usually not continuous along the entire length of the fiber, instead usually forming fibrils which start and end at random. Biconstituent fibers are sometimes also referred to as multiconstituent fibers.

Binder—An adhesive material used to bind a web of fibers together or bond one web to another. The principal properties of a binder are adhesion and cohesion. The binder can be in solid form, for example a powder, film or fiber, in liquid form, for example a solution, dispersion or emulsion or in foam form.

Bonding—The process of securing fibers or filaments to each other in a nonwoven web. The fibers or filaments can be secured by thermal bonding such as in calendering or through air bonding; mechanical means such as in needlepunching; or jets of pressurized fluid such as water in hydroentangling.

Calendering—the process of moving a nonwoven material between opposing surfaces. The opposing surfaces include flat platens, rollers, rollers having projections and combinations thereof. Either or both of the opposing surfaces may be heated.

Card—A machine designed to separate fibers from impurities, to align the fibers and deliver the aligned fibers as a batt or web. The fibers in the web can be aligned randomly or parallel with each other predominantly in the machine direction. The card consists of a series of rolls and drums that are covered with a plurality of projecting wires or metal teeth.

Carded web—A nonwoven web of discontinuous fibers produced by carding.

Carding—A process for making nonwoven webs on a card.

Cellulose fiber—A fiber comprised substantially of cellulose. Cellulosic fibers come from manmade sources (for example, regenerated cellulose fibers or lyocell fibers) or natural sources such as cellulose fibers or cellulose pulp from woody and non-woody plants. Woody plants include, for example, deciduous and coniferous trees. Non-woody plants include, for example, cotton, flax, esparto grass, kenaf, sisal, abaca, milkweed, straw, jute, hemp, and bagasse.

Cellulose material—A material comprised substantially of cellulose. The material may be a fiber or a film. Cellulosic materials come from manmade sources (for example, regenerated cellulose films and fibers) or natural sources such as fibers or pulp from woody and non-woody plants.

Conjugate fiber—A fiber comprising a first fiber portion extending substantially continuously along the length of the fiber and comprising a first thermoplastic polymeric material having a first melting point and a second fiber portion extending substantially continuously along the length of the fiber and defining at least a portion of a fiber exterior surface, the second fiber portion comprising a second thermoplastic polymeric material having a second melting point. Typically, the second melting point is lower than the first melting point. The fiber portions are arranged in substantially constantly positioned distinct zones across the cross-section of the fiber. A conjugate fiber includes fibers comprising two or more polymers or fiber portions. Conjugate fibers are formed by extruding polymer sources from separate extruders through a spinneret to form a single fiber. Typically, different polymeric materials are extruded from each extruder, although a conjugate fiber may encompass extrusion of the same polymeric material from separate extruders. The configuration of conjugate fibers can be symmetric (e.g., sheath:core or side:side) or they can be asymmetric (e.g., offset core within sheath; crescent moon configuration within a fiber having an overall round shape). The shape of the conjugate fiber can be any shape that is convenient to the producer for the intended end use, e.g., round, trilobal, triangular, dog-boned, flat or hollow.

Cross machine direction (CD)—The nonwoven web direction perpendicular to the machine direction.

Denier—A unit used to indicate the fineness of a filament given by the weight in grams for 9,000 meters of filament. A filament of 1 denier has a mass of 1 gram for 9,000 meters of length.

Entanglement—A method of bonding a web by interlocking or wrapping fibers in the web about each other. The method may use mechanical means such as in needlepunching or jets of pressurized fluid such as water in hydroentangling.

Fiber—A material form characterized by an extremely high ratio of length to diameter. As used herein, the terms fiber and filament are used interchangeably unless otherwise specifically indicated.

Filament—A substantially continuous fiber. As used herein, the terms fiber and filament are used interchangeably unless otherwise specifically indicated.

Foam application—A method of applying a material such as a binder or tackifier in a foam form to a fibrous web. The foam form contains less fluid than the same material in a liquid form and thus requires less energy and time to dry the foam and, if applicable, cure the material.

Lyocell—Manmade cellulose material obtained by the direct dissolution of cellulose in an organic solvent without the formation of an intermediate compound and subsequent extrusion of the solution of cellulose and organic solvent into a coagulating bath.

Machine direction (MD)—The long direction of a nonwoven web material that is parallel to and in the direction in which the nonwoven web material is finally accumulated.

Meltblown fiber—A fiber formed by extruding a molten thermoplastic material as filaments from a plurality of fine, usually circular, die capillaries into a high velocity gas (e.g., air) stream which attenuates the filaments of molten thermoplastic material to reduce their diameter. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly dispersed meltblown fibers. The meltblown process includes the melt spray process.

MERV—Minimum Efficiency Reporting Value which is defined in ASHRAE Standard 52.2-1999, Section 11.2.L and Section 12. As an example a MERV 6 filter will have the ability, as per the standard and under its specified conditions, to remove 35% to 50% of a 3-10 micron KCI particle insult. A MERV 7 filter will have the ability to remove 50% to 70% of a 3-10 micron KCI particle insult and a MERV 8 filter will have the ability to remove over 70% of a 3-10 micron KCI particle insult. The higher the MERV number, the higher the filtration performance of a filter.

Monocomponent fiber—A fiber formed from one or more extruders using only one polymer. This is not meant to exclude fibers formed from one polymer to which small amounts of additives have been added for coloration, anti-static properties, lubrication, hydrophilicity, etc. These additives, e.g. titanium dioxide for color, are generally present in low amounts such as less than 5 weight percent.

Needlepunching or Needling—A method of bonding a web by interlocking or wrapping fibers in the web about each other. The method uses a plurality of barbed needles to carry fiber portions in a vertical direction through the web.

Non-thermoplastic polymer—Any polymer material that does not fall within the definition of thermoplastic polymer.

Nonwoven fabric, sheet or web—A material having a structure of individual fibers that are interlaid, but not in an identifiable manner as in a woven or knitted fabric. Nonwoven materials have been formed from many processes such as, for example, meltblowing, spin laying, carding, air laying and water laying processes. The basis weight of nonwoven materials is usually expressed in weight per unit area, for example in grams per square meter (gsm) or ounces per square foot (osf) or ounces per square yard (osy). As used herein a nonwoven sheet includes a wetlaid paper sheet.

Polymer—A long chain of repeating, organic structural units. Generally includes, for example, homopolymers, copolymers, such as for example, block, graft, random and alternating copolymers, terpolymers, etc, and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term “polymer” includes all possible geometrical configurations. These configurations include, for example, isotactic, syndiotactic and random symmetries.

Regenerated cellulose—Manmade cellulose obtained by chemical treatment of natural cellulose to form a soluble chemical derivative or intermediate compound and subsequent decomposition of the derivative to regenerate the cellulose. Regenerated cellulose includes spun rayon and cellophane film. Regenerated cellulose processes include the viscose process, the cuprammonium process and saponification of cellulose acetate.

Short fiber—A fiber that has been formed at, or cut to, lengths of generally one quarter to one half inch (0.6 to 1.3 cm).

Spunlaid filament—A filament formed by extruding molten thermoplastic materials from a plurality of fine, usually circular, capillaries of a spinneret. The diameter of the extruded filaments is then rapidly reduced as by, for example, eductive drawing and/or other well-known mechanisms. Spunlaid fibers are generally continuous with deniers within the range of about 0.1 to 5 or more.

Spunbond nonwoven web—Webs formed (usually) in a single process by extruding at least one molten thermoplastic material as filaments from a plurality of fine, usually circular, capillaries of a spinneret. The filaments are partly quenched and then drawn out to reduce fiber denier and increase molecular orientation within the fiber. The filaments are generally continuous and not tacky when they are deposited onto a collecting surface as a fibrous batt. The spunlaid fibrous batt is then bonded by, for example, thermal bonding, calendering, chemical binders, mechanical needling, hydraulic entanglement or combinations thereof, to produce a nonwoven fabric.

Staple fiber—A fiber that has been formed at, or cut to, staple lengths of generally one quarter to eight inches (0.6 to 20 cm).

Synthetic fiber—a fiber comprised of manmade material, for example glass, polymer, combination of polymers, metal, carbon, regenerated cellulose or lyocell.

Substantially continuous—in reference to the polymeric filaments of a nonwoven web, it is meant that a majority of the filaments or fibers formed by extrusion through orifices remain continuous as they are drawn and then impacted on a collection device. Some filaments may be broken during the attenuation or drawing process, with a substantial majority of the filaments remaining continuous.

Tackifier or Tackiness Agent—a material such as a resin used to impart adhesive properties to otherwise nonadhesive materials such as a nonwoven web. A tackifier can coat the fibers in a nonwoven web to provide the web with adhesive fiber surfaces. Binder resins are typically not tackifiers as curing the binder resin substantially eliminates the ability of the binder to impart adhesive properties to the web.

Tex—A unit used to indicate the fineness of a filament given by the weight in grams for 1,000 meters of filament. A filament of 1 tex has a mass of 1 gram for 1,000 meters of length.

Thermal bonding—A calender process comprising passing a web of fibers to be bonded between a heated calender roll and an anvil roll. The anvil is usually flat. Filaments or fibers in the bonding area are joined by heat and pressure imparted by the rolls. Thermal bonding can also be used to join layers together in a composite material as well as to impart integrity to each individual layer by bonding filaments and/or fibers within each layer.

Thermal point bonding—A thermal bonding process comprising passing a web of fibers to be bonded between a heated calender roll and an anvil roll. The calender roll is patterned in some way so that the fabric is not bonded across its entire surface and the anvil is usually flat. Filaments or fibers in the bonding area are joined by heat and pressure imparted by the rolls. Typically, the percent bonding area varies from around 10% to around 30% of the web surface area. Thermal point bonding can also be used to join layers together in a composite material as well as to impart integrity to each individual layer by bonding filaments and/or fibers within each layer.

Thermoplastic polymer—A polymer that softens and is fusible when exposed to heat, returning generally to its unsoftened state when cooled to room temperature. Thermoplastic materials include, for example, polyvinyl chlorides, some polyesters, polyamides, polyfluorocarbons, polyolefins, some polyurethanes, polystyrenes, polyvinyl alcohol, copolymers of ethylene and at least one vinyl monomer (e.g., poly (ethylene vinyl acetates), and acrylic resins.

Triboelectrically charged fibers—Two yarns of dissimilar polymers that can be rubbed together and exchange charges in such a consistent manner that one fiber forms a positive charge and the other a negative charge.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings wherein like elements are numbered alike in the several Figures:

FIG. 1 is an illustration of preparation of a specimen for the LED score foldability test.

FIG. 2 is an illustration of compression of a specimen for the LED score foldability test.

FIG. 3 is an illustration of measurement of the LED score test angle.

FIG. 4 is an illustration of a Gurley Stiffness specimen showing orientation of the specimen to the nonwoven filtration media.

FIG. 5 is an illustration of a LED Score specimen showing orientation of the specimen to the nonwoven filtration media.

FIG. 6 is a schematic illustration of one embodiment of a thermal bonding system using a single heated roller.

FIG. 7 is a schematic illustration of one embodiment of a thermal bonding system using multiple heated rollers.

FIG. 8 is a graph of MD Gurley Stiffness versus LED foldability for some of the Examples.

DETAILED DESCRIPTION

In one embodiment, a thermally bonded nonwoven filtration media comprising a mixture of discontinuous, fibers is disclosed. The different fibers are substantially homogeneously distributed throughout the thickness of the media. The nonwoven filtration media has an advantageous combination of Gurley Stiffness, foldability within a predetermined range dependent on the Gurley Stiffness and filtration efficiency.

The nonwoven filtration media can be comprised of many different staple length fibers, including synthetic fibers and cellulose fibers. Advantageously, the synthetic fibers include thermoplastic polymer fibers such as one or more of polyester, polyolefin and polyamide. Typically, at least some of the polymer fibers will be conjugate fibers. Advantageously, about 30 percent to about 85 percent of the polymer fibers will be conjugate fibers. As used in this disclosure fiber percentages are by weight of total fibers in the final nonwoven filtration media. Some suitable synthetic fibers are listed below.

Denier Polymer Supplier 4 denier conjugate polyester core Stein of West Point GA and polyester sheath 15 denier Polyester Stein 2.25 denier Polyester RSM of Charlotte, NC 3 denier Polyester Invista of Spartanburg, SC 3 denier Polypropylene American Synthetics of Pendergrass, GA

Triboelectrically charged fibers can comprise a combination of 2 to 4 decitex low finish or scoured polypropylene fibers and 2 to 4 denier scoured modacrylic fibers.

Advantageously the cellulosic fibers include one or more of cotton fibers, rayon fibers, lyocell fibers and kenaf bast fibers. Other cellulosic fibers may be useful in the disclosed nonwoven filtration media. It is believed that the cost of some cellulosic fiber materials, for example lyocell, may limit their use in some applications.

Some suitable cellulosic fibers are listed below.

Denier Polymer Supplier Mixed Polyester/cotton Leigh Fibers of Charlotte, NC 3.33 denier lyocell Tencel of Axis, AL Mixed Cotton Leigh Fibers

The nonwoven filtration media can also comprise a mixture or blend of recycled, staple length polyester fibers and cotton fibers.

The chosen fiber denier for each fiber type of the nonwoven filtration media will be in the range of about 0.1 to about 45. Commercially available nonwoven, higher efficiency (MERV 7 and above), self supporting media, for example pleated air filtration media, use fibers having deniers of 6 and less. Use of fibers having these lower deniers was thought necessary to achieve the desired efficiency (MERV 7 or above). Using fibers with deniers higher than 6 in a self supporting media was not thought desirable as the larger fibers were not thought to provide as efficient a barrier to contamination as smaller fibers and would not allow the media to achieve the desired higher efficiency. Surprisingly and contrary to conventional practice, some of the disclosed embodiments provide a nonwoven, self supporting media having higher efficiency that is formed using a combination of fiber types having small denier fibers in the range of about 6 or less and fiber types having large denier fibers in the range of about 8 to about 45. Advantageously, at least one fiber type is a conjugate fiber. Further, large denier fibers can provide a nonwoven, self supporting, high efficiency media with increased pleat holding ability when compared to a higher efficiency media comprising only small denier fibers. Some disclosed embodiments comprise a nonwoven, self supporting filtration media having an efficiency of MERV 7 or above and including both fiber types having a denier of 6 or less and fiber types having a denier of 8 and above, including a conjugate fiber type. Presently, nonwoven materials comprising 6 denier fibers, for example 6 denier polyester fibers, are excluded from some disclosed embodiments.

Some exemplary staple fibers for use in the disclosed nonwoven filtration media are 0.9 denier monocomponent polyester fibers; 2.25 denier monocomponent polyester fibers; 3 denier monocomponent polyester fibers; 3 denier monocomponent polypropylene fibers; 4 denier polyester core/polyester sheath conjugate fibers; 10 denier polyester core/polyester sheath conjugate fibers; 15 denier monocomponent polyester fibers; 15 denier polyester core/polyester sheath conjugate fibers; 45 denier monocomponent polyester fibers; 2 to 4 decitex low finish or scoured polypropylene fibers; 2 to 4 denier scoured modacrylic fibers; kenaf fibers; and rayon fibers. Naturally, fibers of other deniers, other polymers and other configurations may prove useful in the disclosed nonwoven filtration media.

The nonwoven filtration media will have a basis weight (weight per unit area) of about 0.3 ounces per square foot (osf) (about 90 gsm) and up. The high limit for basis weight will depend on the end use application. Advantageously, the nonwoven filtration media will have a basis weight of about 0.3 osf (about 90 gsm) to about 1.2 osf (about 370 gsm).

The nonwoven filtration media will have a thickness of about 0.04 inches (about 1 mm) to about 0.25 inches (about 6.4 mm) or more depending on the end use application. Advantageously, the nonwoven filtration media will have a thickness of about 0.08 inches (about 2.0 mm) to about 0.12 inches (about 3 mm).

There are numerous known technologies for forming a nonwoven filtration media from staple length fibers, including air laying, wet laying and carding. Presently, carding is considered an advantageous method for making the nonwoven filtration media. Preselected types of staple length fibers are mixed in preselected proportions and the mixture is fed to a card machine. The card machine forms the mixed fibers into a matt. Fibers in the carded matt will be homogeneously distributed, although the majority of fibers will typically be aligned in the machine direction. The matt may optionally be layered using, for example, a cross lapper machine. The cross lapper machine layers the lighter web leaving the card. The carded web enters the cross lapper machine in one direction and the layered matt leaves the cross lapper machine in a direction perpendicular to the entry direction. The layered matt will typically have an increased basis weight as compared to the carded matt. The layered maft may have a cross direction fiber orientation, although fibers in the layered maft are typically more randomly oriented than in the carded matt.

Many technologies can be employed to join or bond the fibers in the matt. Some useful bonding technologies include, for example, one or more of entangling, thermal calendering of the matt to fuse thermoplastic fibers therein, application of ultrasonic energy to the matt and/or application of resin materials to the matt. Presently, mechanical entanglement such as needlepunching is considered advantageous forjoining fibers of the matt.

Heat can be applied to the entangled matt to at least partially melt the thermoplastic fibers therein. Upon cooling, the melted thermoplastic fibers harden and fuse the fibers in the entangled matt. One advantageous method of thermal bonding is running the entangled matt over one or more heated rolls. The media can be threaded through the system utilizing additional rolls, which may not be shown, to heat one or both sides of the entangled matt. FIG. 6 schematically illustrates one embodiment of a thermal bonding system using a single heated roller. FIG. 7 schematically illustrates one embodiment of a thermal bonding system using multiple heated rollers. The third roll in FIG. 7 can optionally be moved into contact with the opposite side of the matt for compression and heating of the matt. The rolls are heated to a temperature sufficient to soften and fuse the thermoplastic fibers. Suitable temperatures are generally in the range of about 300° F. to about 420° F., depending on the matt contact time. The thermally bonded matt can optionally be further bonded by passing the matt through ovens after thermal bonding over heated rollers. It may be possible to thermal bond the matt by oven heating alone to form the disclosed nonwoven filtration media. Nonwoven filtration media bonded using both heated rollers and oven are exemplified in examples 166, 180 and 211.

Resin binders can be added to the nonwoven filtration media after carding or bonding. Some suitable resin binders are ethylene vinyl chloride, ethylene vinyl acetates, acrylics and acrylates. Resin binders are typically applied as a solution and are dried and/or cured by heating. The resin binder solution can be added using conventional processes, for example, by spraying, dipping or foaming the matt. Resin binders are typically non-adhesive after curing.

The nonwoven filtration media can be coupled to a second nonwoven web to form a composite filtration media. The second nonwoven web can be comprised of continuous filaments, for example a spunbonded web, or discontinuous fiber, for example a carded web or a wet laid web. Typically, the coupled media and web will be in continuous face to face contact. The coupled webs can be joined by adhesive bonding; thermal bonding; mechanical entanglement or ultrasonic bonding. Alternately, the nonwoven filtration media can be used as a base over which charged fibers, such as triboelectrically charged fibers, can be laid and mechanically entangled. Additionally, different layers comprising cotton and polyester-cotton mixtures layers can be layered between the nonwoven filtration media and the triboelectrically charged fibers. See Table 5, Examples 208 to 210.

After formation and bonding, the filtration media material may be charged or corona treated. Corona treatment further increases filtration efficiency by drawing particles to be filtered toward the nonwoven filtration media by virtue of its electrical charge. Corona treatment can be carried out by a number of different techniques. One technique is described in U.S. Pat. No. 5,401,446 to Tsai et al. assigned to the University of Tennessee Research Corporation and incorporated herein by reference in its entirety. Other methods of corona treatment are known in the art.

The disclosed nonwoven filtration media may be made into a filter by any suitable means known in the art, for example by rotary pleating. Rotary pleating, while faster than many other pleating methods, is indicated to be quite dependent upon the stiffness of the filter medium. Gurley Stiffness values of at least 600 mg are required to allow pleating on high speed rotary pleating equipment. Other methods of pleating are not as sensitive to filtration media stiffness but are slower. Rotary pleating is discussed in, for example, U.S. Pat. No. 5,709,735 to Midkiff and Neely.

In one advantageous embodiment one or more tackifiers are coated over fibers of the nonwoven media. A tackifier is a natural or synthetic material that adheres to, and provides a long lasting sticky or adhesive surface on, the fibers of the nonwoven filtration media. Some suitable tackifiers include elastomeric polymeric emulsions such as HYSTRETCH® elastomeric emulsions available from Lubrizol Advanced materials of Pittsburgh, Pa.; FLEXCRYL® adhesive emulsions available from Air Products Polymers L.P. of Allentown, Pa.; and SPAR CRYL materials available from Spartan Chemical Laboratories, Inc. of Spartanburg, S.C. The amount of tackifier added to the nonwoven filtration media can typically be in the range of about 0.5 percent by weight of the nonwoven filtration media to about 30 percent by weight of the nonwoven filtration media. Advantageously, the amount of tackifier added to the nonwoven filtration media can be in the range of about 1.5 percent by weight of the nonwoven filtration media to about 15 percent by weight of the nonwoven filtration media. The preferred amount of tackifier in some embodiments can be in the range of about 1.5% to about 6% while in other embodiments the amount of tackifier can be in the range of about 1.5% to about 3%.

Tackifiers are typically applied as an emulsion, solution or foam and excess fluid removed, for example by heating. The tackifier emulsion or solution can be added using conventional processes, for example, by foaming, spraying brushing or dipping the nonwoven filtration media.

In one presently preferred method, preselected types of staple length fibers are mixed in preselected proportions. The staple length fiber mixture is fed to a card machine. The card machine forms the mixed, staple length fibers into a matt. The matt is cross lapped to increase basis weight and rearrange fiber orientation. The carded and lapped matt is needle punched to mechanically entangle the fibers therein. The entangled matt is thermally bonded by running the matt over one or more heated rolls. The matt can also be optionally compressed by rolls during thermal bonding. Liquid resin binders are optionally applied to the thermal bonded matt. The binder comprising matt is heated to dry the matt and/or to cure the binder. A nonwoven web can optionally be superimposed on the carded matt prior to needle punching so that the carded matt and nonwoven web are mechanically entangled into a composite filtration media.

A tackifier, typically in solution, can be added to the nonwoven filtration media at any convenient point during manufacturing. Application of a tackifier solution to the fibers before carding or to the carded matt before thermal bonding can lead to problems with formation of the desired nonwoven filtration media. It is advantageous to apply the tackifier to the nonwoven filtration media after thermal bonding of the fibers.

As discussed above the nonwoven filtration media has an advantageous combination of Gurley Stiffness, foldability within a predetermined range dependent on the Gurley Stiffness and filtration properties. Filtration properties can be quantified using tests such as Frazier Permeability, dP, PFE efficiency and Index. Test methods are discussed below.

Frazier Air Permeability

Frazier air permeability test is a measure of the permeability of a filtration media to air. The Frazier test is performed in accordance with ASTM D461-72, D737-75, F778-82, TAPPI T251 and ISO 9237, and is reported as an average of 4 sample readings. The test reports the amount of air that flows in cubic feet per minute per square foot at a resistance of 0.5″ water gauge. CFM/square foot results can be converted to liters per square meter per minute (LSM) by multiplying CFM/square foot by 304.8. It is believed advantageous that the disclosed nonwoven filtration media have a Frazier Permeability in the range of about 150 CFM/square foot to about 850 CFM/square foot.

dP and PFE Efficiency

dP and PFE are test results from ASHRAE standard ASHRAE 52.2-1999. dP is pressure drop or resistance as measured in inches of water gauge at 110 feet per minute air velocity. PFE is the particle fraction efficiency percentage removal efficiency at 110 feet per minute air velocity. One reportable PFE range averages the efficiency between 3 to 10 micron particle sizes and another reportable range averages the efficiency between the 1 to 3 micron particle sizes. It is believed advantageous that the disclosed nonwoven filtration media have a dP in the range of about 0.03 to about 0.22. inches water gauge and a 3 to 10 micron range particle fraction efficiency of between 17.8% and 93.3% and/or a 1 to 3 micron range particle fraction efficiency of between 1.5% and 71.4%.

Index

Index is calculated using the PFE result for 3 to 10 micron efficiency divided by dP. Index is unitless. It is believed advantageous that the disclosed nonwoven filtration media have an Index in the range of about 300 to about 1600.

Gurley Stiffness

Gurley Stiffness measures nonwoven filtration media stiffness. The Gurley Stiffness test method, discussed in more detail below, generally follows TAPPI Method T 543 om-94. Gurley stiffness is measured in the machine direction (MD) and results are reported in milligrams.

-   -   1) Level the tester using the bubble level on front/top.     -   2) Obtain a square foot sample of media with the MD marked on         it, ensuring the product has not been excessively handled or         bent.     -   3) With reference to FIG. 4, cut three specimens across the         width that are 1″×2″ with 2″ side being parallel to the CD. Mark         samples “CD”. These samples reflect flexure in the MD plane and         are used to obtain MD Gurley stiffness values.     -   4) Cut three specimens across the width that are 2″×1″ with 2″         side being parallel to the MD. Mark samples “CD”. These samples         reflect flexure in the CD plane and are used to obtain CD Gurley         stiffness values.     -   5) Set up tester as in table below.     -   6) Orient the specimen in Gurley holder with 2″ side in jaws and         fuzzy (AIR ENTERING) side facing right, position sample to the         right.     -   7) Always start first arm movement from right to left.     -   8) Once media releases from vane stop all movement. Wait one         minute to allow arm movement to slow and stop it (+/−¼″) gently.     -   9) Start arm movement to left until media releases from vane.     -   10) Push the converter button and record the record values.     -   11) Average the three tests for both MD and CD separately and         report average of three for each.

Parameter Setting Length (inches) 1.5 Width (inches) 2.0 Weight position (inches) 2.0 Weight (grams) 200 The stiffer the nonwoven, the higher the Gurley stiffness reading. A Gurley Bending Resistance Tester model 4171D available from Gurley Precision Instruments of Troy, N.Y. has been found suitable for the above testing.

LED Foldability Score

The “LED score” test measures the ability of a nonwoven media to accept and retain a fold. The “LED score” test is similar to a Shirley Crease Retention Test, (American Association of Textile and Color Chemists (AATCC)-66-2003 et al). Briefly, the “LED score” test is performed using the following procedure:

-   -   1) Obtain specimen.     -   2) With reference to FIG. 5, cut specimen into a ½″ wide×4″ long         test sample with long direction parallel to CD.     -   3) Place test sample on flat metal surface.     -   4) Place angle iron in contact with test sample with apex         against sample.     -   5) Strike angle iron once with 1170 gram hammer.     -   6) Fold test sample at score and place in file folder type         cardboard sleeve. See FIG. 1.     -   7) Place folded test sample and sleeve under 1800 gram weight         for 30 seconds. See FIG. 2.     -   8) Remove weight from folded test sample and sleeve and remove         test sample from sleeve keeping it closed.     -   9) Position test sample vertically immediately in front of         measuring apparatus.     -   10) Release and slip vertical leg of test sample into measuring         apparatus.     -   11) Within 3 to 5 seconds align bottom of protractor portion         with free leg of test sample.     -   12) Read “LED Score” test result. See FIG. 3.     -   13) Repeat three times for each specimen.     -   14) Average results.         The measured angle is related to the nonwoven filtration media's         resistance to opening, e.g. the ability to retain a fold or         pleat. The more foldable a nonwoven, the higher the LED score         angle.

The right combination or range of Gurley stiffness and retained foldability properties allows a nonwoven filtration media material to accept and hold a better fold or pleat with a straighter line between the fold peak and valley than other nonwoven filtration medias having properties outside of this range. Such combinations of Gurley stiffness and retained foldability properties are desirable in the manufacture of filter products. Naturally, not every nonwoven will have the advantageous combinations of Gurley stiffness and retained foldability properties disclosed herein. Further, even nonwoven media having similar combinations of Gurley stiffness and retained foldability properties to those disclosed herein will not have the presently disclosed filtration properties.

Filters used in heating, ventilation and air conditioning (HVAC) systems can comprise a peripheral housing defining an open center with nonwoven filtration media sealed to the housing and spanning the open center. The housing allows the filter to be handled and sealed to the HVAC system. Air to be filtered is moved through the media. Thus, during use the nonwoven filtration media is subjected to a pressure drop caused by air movement through that media. The filter and nonwoven filtration media are also subjected to varying temperature and humidity conditions depending on geographic location and time of year.

Some nonwoven media cannot maintain their shape, for example pleats, when subjected to the pressure drop and varying temperature and humidity conditions of a HVAC system unless one or both faces of the nonwoven media is supported by an open mesh framework spanning the edges of the housing.

In some embodiments the disclosed nonwoven filtration media is self supporting, that is the media has a combination of MD Gurley stiffness and retained (LED) foldability to allow it to maintain its shape when used in a HVAC system without requiring face support by an open mesh framework spanning the edges of the housing.

In some advantageous embodiments of the disclosed nonwoven filtration media the MD Gurley stiffness is above about 2400 milligrams and the retained (LED) foldability is maintained between about 39.3 degrees and about 134 degrees. In some other advantageous embodiments of the disclosed nonwoven filtration media the MD Gurley stiffness is below 2400 milligrams and retained (LED) foldability is maintained between about 40 degrees and about 108 degrees.

Especially advantageous combinations of Gurley stiffness and retained (LED) foldability (wherein ranges are indicated by letters A to H) are shown in Table 1.

TABLE 1 Range Gurley Stiffness - MD (mg) LED Foldability (degrees) A Over 3000 60.2 to 101.7 B 2800 to 3000 55.0 to 104.2 C 2400 to 2800 53.3 to 101.5 D 1800 to 2400 39.7 to 108.2 E 1400 to 1800 41.2 to 98.3  F 1200 to 1400 77.0 to 86.0  G  800 to 1200 39.3 to 68.2  H Under 800 42.7 to 68.8 

As illustrated in Table 1 and FIG. 8, foldability is seen to increase with MD Gurley stiffness.

Having generally described the invention, the following examples and those on the attached Tables are included for purposes of illustration so that the invention may be more readily understood and are in no way intended to limit the scope of the invention unless otherwise specifically indicated. The Examples were comprised of staple fibers in the combinations shown on the Tables and were prepared using conventional carding and cross lapping equipment and conditions. Unless otherwise noted the examples were bonded using heated rollers, sometimes in combination with oven heating unless otherwise indicated. Some examples were bonded using ultrasonic energy. Table 5 lists bonding conditions for some examples.

Nonwoven Filtration Media Comprising a Mix of Staple Length Fibers Having a Denier of 4 or Less and 10 or More.

Example 2 in range A was prepared by carding and fibers to form a nonwoven matt. The matt was thermally bonded over heated rollers. This filtration media comprises 85% staple length fibers having a denier of 4 or less and 15% staple length fibers having a denier of 10 or more. 70% of the fibers of Example 2 are staple length conjugate fibers having a denier less than 4 and a lower melting point polyester sheath, higher melting point polyester core. The fibers are homogeneously distributed throughout the single layer media. This nonwoven filtration media has a basis weight of about 177 gsm, a Frazier permeability of about 321 CFM/square foot, a dP of about 0.18, a PFE efficiency of about 58, a MD Gurley stiffness of about 3266 milligrams and a LED score test result of about 62 degrees.

Example 17 in range C was prepared by carding and fibers to form a nonwoven matt. The matt was thermally bonded over heated rollers. This filtration media comprises 75% staple length fibers having a denier of 4 or less and 25% staple length fibers having a denier of 10 or more. 50% of the fibers of Example 17 are staple length conjugate fibers having a denier less than 4 and a lower melting point polyester sheath, higher melting point polyester core. The fibers are homogeneously distributed throughout the single layer media. This nonwoven filtration media has a basis weight of about 180 gsm, a Frazier permeability of about 615 CFM/square foot, a MD Gurley stiffness of about 2630 milligrams and a LED score test result of about 66 degrees.

Example 50 in range E was prepared by carding and fibers to form a nonwoven matt. The matt was thermally bonded over heated rollers. This filtration media comprises 75% staple length fibers having a denier of 4 or less and 25% staple length fibers having a denier of 10 or more. 75% of the fibers of Example 50 are staple length conjugate fibers having a denier less than 4 and a lower melting point polyester sheath, higher melting point polyester core. The fibers are homogeneously distributed throughout the single layer media. This nonwoven filtration media has a basis weight of about 131 gsm, a Frazier permeability of about 580 CFM/square foot, a dP of about 0.076, a PFE efficiency of about 44, a MD Gurley stiffness of about 1770 milligrams and a LED score test result of about 85 degrees.

Nonwoven Filtration Media Comprising Staple Length Fibers all Having a Denier of 5 or Less.

Example 8 in range B was prepared by carding and fibers to form a nonwoven matt. The matt was thermally bonded over heated rollers. This filtration media comprises 80% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 10% 0.9 denier staple length polyester fibers; and 10% 2.25 denier staple length polyester fibers. The fibers are homogeneously distributed throughout the single layer media. This nonwoven filtration media has a basis weight of about 150 gsm, a Frazier permeability of about 409 CFM/square foot, a dP of about 0.12, a PFE efficiency of about 50, a MD Gurley stiffness of about 2900 milligrams and a LED score test result of about 91 degrees.

Example 38 in range D was prepared by carding and fibers to form a nonwoven matt. The matt was thermally bonded over heated rollers. This filtration media comprises 52% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 5% 0.9 denier staple length polyester fibers; and 43% 2.25 denier staple length polyester fibers. The fibers are homogeneously distributed throughout the single layer media. This nonwoven filtration media has a basis weight of about 180 gsm, a Frazier permeability of about 340 CFM/square foot, a dP of about 0.16, a PFE efficiency of about 62, a MD Gurley stiffness of about 2000 milligrams and a LED score test result of about 40 degrees.

Nonwoven Filtration Media Comprising Staple Length Kenaf Fibers.

Example 18 in range C was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises 50% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 25% 4 denier staple length polyester fibers; and 25% staple length kenaf fibers. The fibers are homogeneously distributed throughout the single layer media. This nonwoven filtration media has a basis weight of about 165 gsm, a Frazier permeability of about 460, a dP of about 0.1, a PFE efficiency of about 52, a MD Gurley stiffness of about 2585 milligrams and a LED score test result of about 64.5 degrees.

Example 21 in range C was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises 70% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 15% 4 denier staple length polyester fibers; and 15% staple length kenaf fibers. The fibers are homogeneously distributed throughout the single layer media. This filtration media has a basis weight of about 168 gsm, a Frazier permeability of about 430, a dP of about 0.1, a PFE efficiency of about 48, a MD Gurley stiffness of about 2515 and a LED score test result of about 69.7 degrees.

Example 61 in range E was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises 40% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 35% 4 denier staple length polyester fibers; and 25% staple length kenaf fibers. The fibers are homogeneously distributed throughout the single layer media. This filtration media has a basis weight of about 160 gsm, a Frazier permeability of about 525, a dP of about 0.08, a PFE efficiency of about 54, a MD Gurley stiffness of about 1650 milligrams and an LED score test result of about 64.5 degrees.

Example 82 in range F was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises 30% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 35% 4 denier staple length polyester fibers; and 35% staple length kenaf fibers. The fibers are homogeneously distributed throughout the single layer media. This filtration media has a basis weight of about 160 gsm, a Frazier permeability of about 530, a dP of about 0.08, a PFE efficiency of about 48, a MD Gurley stiffness of about 1297 milligrams and an LED score test result of about 63.5 degrees.

Nonwoven Filtration Media Comprising a Blend of Recycled, Staple Length, Polyester Fibers and Cotton Fibers.

Example 29 in range D was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises 70% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 15% 0.9 denier staple length polyester fibers; and 15% of a blend of recycled, staple length, polyester fibers and cotton fibers. The fibers are homogeneously distributed throughout the single layer media. One side of the media was run over a roller heated to 380° F. to partially melt and fuse the fibers. This filtration media has a basis weight of about 190 gsm, a Frazier permeability of about 290, a dP of about 0.2, a PFE efficiency of about 66, a MD Gurley stiffness of about 2209 milligrams and a LED score test result of about 63.3 degrees.

Example 30 in range D was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises 70% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; and 30% of a blend of recycled, staple length, polyester fibers and cotton fibers. The fibers are homogeneously distributed throughout the single layer media. One side of the media was run over a roller heated to 400° F. to partially melt and fuse the fibers. This filtration media has a basis weight of about 200 gsm, a Frazier permeability of about 330, a dP of about 0.16, a PFE efficiency of about 73, a MD Gurley stiffness of about 2195 milligrams and a LED score test result in the range of about 53.0 degrees.

Nonwoven Filtration Media Comprising Staple Length Polypropylene Fibers.

Example 75 in range E was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises about 65% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 15% 3 denier staple length uncharged polypropylene fibers; and 20% 0.9 denier staple length polyester fibers. The fibers are homogeneously distributed throughout the single layer media. This filtration media has a basis weight of about 116 gsm, a Frazier permeability of about 418, a MD Gurley stiffness of between about 1411 milligrams and a LED score test result in the range of about 66.5 degrees.

Example 77 in range F was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises about 40% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; about 30% 3 denier staple length uncharged polypropylene fibers; and about 30% 15 denier staple length polyester fibers. The fibers are homogeneously distributed throughout the single layer media. One side of the media was run over a roller heated to about 352° F. to partially melt and fuse the fibers. This filtration media has a basis weight of about 160 gsm, a Frazier permeability of about 514, a dP of about 0.08, a PFE efficiency of about 41, a MD Gurley stiffness of about 1371 milligrams and a LED score test result of about 50.8 degrees.

Example 105 in range G was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises about 60% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 25% 3 denier staple length uncharged polypropylene fibers; and about 15% 15 denier staple length polyester fibers. The fibers are homogeneously distributed throughout the single layer media. One side of the media was run over a roller heated to about 352° F. to partially melt and fuse the fibers. This filtration media has a basis weight of about 113 gsm, a Frazier permeability of about 613, a MD Gurley stiffness of about 955 milligrams and a LED score test result in the range of about 65.0 degrees.

Example 111 in range H was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises 40% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 30% 3 denier staple length uncharged polypropylene fibers; and about 30% 15 denier staple length polyester fibers. The fibers are homogeneously distributed throughout the single layer media. One side of the media was run over a roller heated to about 352° F. to partially melt and fuse the fibers. This filtration media has a basis weight of about 120 gsm, a Frazier permeability of about 630, a MD Gurley stiffness of about 637 milligrams and a LED score test result of about 56.7 degrees.

Nonwoven Filtration Media Comprising 10 Denier, Staple Length, Conjugate Polyester Fibers.

Example 85 in range F was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises about 35% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; about 35% 10 denier, staple length conjugate polyester fibers; and about 30% 0.9 denier staple length polyester fibers. The fibers are homogeneously distributed throughout the single layer media. This filtration media has a basis weight of about 116 gsm, a Frazier permeability of about 500, a dP of about 0.1, a PFE efficiency of about 48, a MD Gurley stiffness of about 1258 milligrams and a LED score test result in the range of about 59.5 degrees.

Example 104 in range G was prepared by carding and heat bonding fibers to form a nonwoven filtration media. This filtration media comprises 55% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; 10% 10 denier, staple length conjugate polyester fibers; and 35% 3 denier staple length polyester fibers. The fibers are homogeneously distributed throughout the single layer media. This filtration media has a basis weight of about 120 gsm, a Frazier permeability of about 560, a dP of about 0.08, a PFE efficiency of about 38, a MD Gurley stiffness of about 960 milligrams and a LED score test result of about 68.2 degrees.

Nonwoven Filtration Media Comprising More than One Layer.

Example 19 in range C was prepared by carding and heat bonding fibers to form a first nonwoven filtration media. This first nonwoven media includes about 70% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and about 30% 15 denier polyester fibers. The first filtration media was needled onto a second spunbond nonwoven filtration media comprising 0.5 osy polypropylene filaments to form the nonwoven composite material. One side of the composite material was run over a roller heated to about 320° F. to partially melt and fuse the fibers. This nonwoven composite material has a basis weight of about 168 gsm, a Frazier permeability of about 530, a MD Gurley stiffness of about 2583 milligrams and a LED score test result of about 74.0 degrees.

Example 26 in range D was prepared by carding and heat bonding fibers to form a first nonwoven filtration media. This first nonwoven media includes about 70% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and about 30% 15 denier staple length polyester fibers. The first filtration media was needled onto a second spunbond nonwoven filtration media comprising 0.5 osy polypropylene filaments to form the nonwoven composite material. One side of the material was run over a roller heated to about 335° F. to partially melt and fuse the fibers. This nonwoven composite material has a basis weight of about 153 gsm, a Frazier permeability of about 540, a dP of about 0.07, a PFE efficiency of about 44, a MD Gurley stiffness of about 2298 milligrams and a LED score test result of about 86.7 degrees.

Example 169 in range D is a 2 layer nonwoven filtration media. Each layer was an independently carded matt formed using a different card machine. One carded matt comprised 50% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and 50% 3 denier, staple length polyester fibers. The other carded matt comprised 50% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and 50% 45 denier, staple length polyester fibers. Each carded matt was cross lapped using a separate cross lapper. The cross lapped matts were overlaid, mechanically entangled by needling and thermally bonded using a heated roller. Each carded matt contributed one half to the weight of this 2 layer nonwoven filtration media. This nonwoven composite material has a basis weight of about 150 gsm, a Frazier permeability of about 500, a dP of about 0.075, a PFE efficiency of about 45, a MD Gurley stiffness of about 2300 milligrams and a LED score test result of about 73 degrees.

Resin and Thermal Bonded Nonwoven Filtration Media.

Nonwoven filtration medias can be bonded using liquid resins or binders.

Example 180 in range D was prepared by carding fibers to form a matt. This matt comprises about 15% 2.25 denier staple length, monocomponent polyester fibers; about 50% 15 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and about 35% 45 denier staple length, monocomponent polyester fibers. The fibers are homogeneously distributed throughout the single layer media. One side of the matt was heated over a heated roller to partially melt and fuse the fibers. A solution of resin binder was applied to the heat bonded matt. The impregnated matt was run through an oven having multiple heating zones with each zone heated to between 241 and 298° F. This filtration media has a resin content of about 15 percent by weight of the media, a basis weight of about 140 gsm, a Frazier permeability of about 580, a dP of about 0.04, a PFE efficiency of about 30, a and a MD Gurley stiffness of about 1965 milligrams and a LED score test result of about 94 degrees.

Example 194 in range F was prepared by carding fibers to form a matt. This matt comprises about 35% 3 denier staple length, monocomponent polyester fibers; about 50% 15 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and about 15% 45 denier staple length, monocomponent polyester fibers. The fibers are homogeneously distributed throughout the single layer media. A solution of resin binder was applied to the heat bonded matt. One side of the matt was heated over a heated roller to partially melt and fuse the fibers and dry the resin binder. This filtration media has a resin content of about 15 percent by weight of the media, a basis weight of about 150 gsm, a Frazier permeability of about 614, a MD Gurley stiffness of about 1371 milligrams and a LED score test result of about 72 degrees.

Example 211 in range C was prepared by carding fibers to form a matt. This matt comprises about 10% 4 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers; about 65% 15 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and about 25% 45 denier staple length, monocomponent polyester fibers. The fibers are homogeneously distributed throughout the single layer media. One side of the matt was heated over a heated roller to partially melt and fuse the fibers. A solution of resin binder was applied to the heat bonded matt. The impregnated matt was run through an oven having multiple heating zones with each zone heated to between 186 and 220° F. This filtration media has a resin content of about 15 percent by weight of the media, a basis weight of about 165 gsm, a Frazier permeability of about 671, a dP of about 0.033, a PFE efficiency of about 18, a MD Gurley stiffness of about 2615 milligrams and a LED score test result of about 101.5 degrees.

Ultrasonic Bonded Nonwoven Filtration Media.

Nonwoven filtration medias can be bonded using ultrasonic energy. Ultrasonic bonding is generally performed using a specifically tuned horn vibrating at a high frequency in close proximity to an anvil roll. The anvil roll can either be flat or have a pattern engraved into the roll.

Example 116 in range H was prepared by carding and ultrasonic bonding fibers to form a nonwoven filtration media. This filtration media comprises about 25% 15 denier polyester fibers; about 25% 45 denier polyester fibers and about 50% 3 denier polypropylene fibers. The fibers are homogeneously distributed throughout the single layer media. This nonwoven filtration media was ultrasonically bonded using a flat anvil roll, a horn and a frequency of 20 kHz, a step position of 7378 with a target force of 800 Newtons on a Hermann Ultrasonics laboratory scale unit (Schaumberg, Ill.). This filtration media has a basis weight of about 170 gsm, a Frazier permeability of about 413, a MD Gurley stiffness of about 140 milligrams and a LED score test result of about 73.3 degrees.

Tackified Nonwoven Filtration Media 1

Examples 218 and 219 and Example 220 were prepared by carding and cross lapping fibers to form a matt. This matt comprises about 63% 4 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers, about 17% 15 denier staple length, monocomponent polyester fibers and about 20% 3 denier staple length, monocomponent polyester fibers. The fibers are substantially homogeneously distributed throughout the single layer media.

One side of the matt was heated over a heated roller to partially melt and fuse the fibers. No tackifier or tack agent was applied to the media of Examples 218, 219 and 220.

This filtration media has a basis weight of about 157 gsm, a Frazier permeability of about 496, a dP of about 0.073, a PFE efficiency of about 51.8, an index of about 710, a and a MD Gurley stiffness of about 2493 milligrams and a LED score test result of about 66.1 degrees.

Examples 221, 222 and 223 used the media of examples 218 to 220. An aqueous emulsion of Hystretch V-60 tack agent was sprayed against one side of the media to provide the add-ons shown in Table 6. Examples 221 and 222 were dried by running through a three zone forced air dryer with zone temperatures of about 280° F., 320° F. and 350° F. Example 223 was dried in still air at ambient temperatures (about 78° F.) for about 14 hours so as to dry the media to the touch. Physical properties of these Examples are illustrated on Table 6.

Examples 224, 225, 226, 227 and 228 used the media of examples 218 to 220. An aqueous emulsion of Hystretch V-60 tack agent, available from Lubrizol of Pittsburgh, Pa., was sprayed against both sides of the media to provide the add-ons shown in Table 6. Examples 224 and 225 were dried by running through a three zone forced air dryer with zone temperatures of about 280° F., 320° F. and 350° F. Examples 226, 227 and 228 were dried in still air at ambient temperatures (about 65° F. to about 78° F.) for about 14 hours so as to dry the media to the touch. Physical properties of these Examples are illustrated on Table 6.

Example 229 used the media of examples 218 to 220. An aqueous emulsion of Flexacryl 1625 tack agent, available from Air Products Polymers of Allentown, Pa., was sprayed against both sides of the media to provide the add-ons shown in Table 6. Example 229 was dried in still air at ambient temperatures (about 65° F.) for about 14 hours so as to dry the media to the touch. Physical properties of these Examples are illustrated on Table 6.

Examples 230 and 231 used the media of examples 218 to 220. An aqueous emulsion of Spar Cryl 102 tack agent, available from Spartan Chemical Laboratories, Inc of Spartanburg, S.C., was sprayed against both sides of the media to provide the add-ons shown in Table 6. Examples 230 and 231 were dried in still air at ambient temperatures (about 65° F.) for about 14 hours so as to dry the media to the touch. Physical properties of these Examples are illustrated on Table 6.

Tackified Nonwoven Filtration Media 2

Examples 232 and 233 were prepared by carding and cross lapping fibers to form a matt. This matt comprises about 50% 15 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers, about 15% 2.25 denier staple length, monocomponent polyester fibers and about 35% 45 denier staple length, monocomponent polyester fibers. The fibers are substantially homogeneously distributed throughout the single layer media.

One side of the matt was heated over a heated roller to partially melt and fuse the fibers. No tackifier or tack agent was applied to the media of Examples 232 and 233.

This filtration media has a basis weight of about 159 gsm, a Frazier permeability of about 621, a dP of about 0.051, a PFE efficiency of about 43.3, an index of about 847, a MD Gurley stiffness of about 1872 milligrams and a LED score test result of about 78.6 degrees.

Examples 234 and 235 used the media of examples 232 to 233. An aqueous emulsion of Hystretch V-60 tack agent was sprayed against one side of the media to provide the add-ons shown in Table 6. Examples 234 and 235 were dried in still air at ambient temperatures (about 78° F.) for about 14 hours so as to dry the media to the touch. Physical properties of these Examples are illustrated on Table 6.

Examples 236, 237 and 238 used the media of Examples 232 and 233. An aqueous emulsion of Hystretch V-60 tack agent, available from Lubrizol of Pittsburgh, Pa., was sprayed against both sides of the media to provide the add-ons shown in Table 6. Examples 236 and 237 were dried in still air at ambient temperatures (about 78° F.) for about 14 hours so as to dry the media to the touch. Example 238 was dried by running through a three zone forced air dryer with zone temperatures of about 280° F., 320° F. and 350° F. Physical properties of these Examples are illustrated on Table 6.

Tackified Nonwoven Filtration Media 3

Example 239 comprises about 38% 15 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers, about 11.4% 2.25 denier staple length, monocomponent polyester fibers, about 26% 45 denier staple length, monocomponent polyester fibers, about 12% 3.3 denier staple length, triboelectrically chargeable polypropylene fibers and about 12% 3 denier staple length, triboelectrically chargeable modacrylic fibers. Example 239 was prepared by carding and cross lapping a combination of 50% 15 denier conjugate fibers, 15% 2.25 denier polyester fibers and 35% 45 denier polyester fibers to form a matt. The malt was entangled by needling and heated over a heated roller to partially melt and fuse the fibers. The tribocharged fibers (about 12% 3.3 denier staple length, triboelectrically chargeable polypropylene fibers and about 12% 3 denier staple length, triboelectrically chargeable modacrylic fibers) were homogeneously blended, applied over the matt and entangled into the matt using needling. The matt and entangled, tribocharged fibers were heated over a heated roller to partially melt and fuse the fibers. No tackifier or tack agent was applied to the media of Examples 239.

This filtration media has a basis weight of about 159 gsm, a Frazier permeability of about 505, a dP of about 0.077, a PFE efficiency of about 77.9, an index of about 1012, a MD Gurley stiffness of about 1731 milligrams and a LED score test result of about 65.3 degrees.

Example 240 used the media of example 239. An aqueous emulsion of Hystretch V-60 tack agent, available from Lubrizol of Pittsburgh, Pa., was sprayed against both sides of the media to provide the add-ons shown in Table 6. Example 240 was dried in still air at ambient temperatures (about 65° F.) for about 14 hours so as to dry the media to the touch.

Example 241 used the media of example 239. An aqueous emulsion of Flexacryl 1625 tack agent, available from Air Products Polymers of Allentown, Pa., was sprayed against both sides of the media to provide the add-ons shown in Table 6. Example 241 was dried in still air at ambient temperatures (about 78° F.) for about 14 hours so as to dry the media to the touch.

Example 242 used the media of examples 239. An aqueous emulsion of Spar Cryl 102 tack agent, available from Spartan Chemical Laboratories, Inc of Spartanburg, S.C., was sprayed against both sides of the media to provide the add-ons shown in Table 6. Example 242 was dried in still air at ambient temperatures (about 78° F.) for about 14 hours so as to dry the media to the touch.

Physical properties of these Examples are illustrated on Table 6.

Tackified, Two Layer, Nonwoven Filtration Media 4

Example 243 is a 2 layer nonwoven filtration media. Each layer was an independently carded matt formed using a different card machine. One carded matt comprised 50% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and 50% 3 denier, staple length polyester fibers. The other carded matt comprised 50% 4 denier, staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and 50% 3 denier, staple length polyester fibers. Each carded matt was cross lapped using a separate cross lapper.

The cross lapped matts were overlaid, mechanically entangled by needling. One side of the entangled matts was run over a heated roller to partially melt and fuse the fibers in the media. Each carded matt contributed one half to the weight of this 2 layer nonwoven filtration media. No tackifier or tack agent was applied to the media of Examples 243.

This filtration media has a basis weight of about 150 gsm, a Frazier permeability of about 500, a dP of about 0.075, a PFE efficiency of about 45.4, an index of about 605, a MD Gurley stiffness of about 2300 milligrams and a LED score test result of about 71.6 degrees.

Example 244 used the media of example 243. An aqueous emulsion of Hystretch V-60 tack agent, available from Lubrizol of Pittsburgh, Pa., was sprayed against both sides of the media to provide the add-ons shown in Table 6. Example 244 was dried by running through a three zone forced air dryer with zone temperatures of about 280° F., 320° F. and 350° F. Physical properties of this Example are illustrated on Table 6.

Tackified Nonwoven Filtration Media 5

Example 245 was prepared by carding and cross lapping fibers to form a matt. This matt comprises about 50% 4 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers, about 8% 0.9 denier staple length, monocomponent polyester fibers and about 43% 2.25 denier staple length, monocomponent polyester fibers. The fibers are substantially homogeneously distributed throughout the single layer media.

One side of the matt was heated over a heated roller to partially melt and fuse the fibers. No tackifier or tack agent was applied to the media of Example 245.

This filtration media has a basis weight of about 174 gsm, a Frazier permeability of about 230, a dP of about 0.169, a PFE efficiency of about 88.3, an index of about 522, a MD Gurley stiffness of about 1965 milligrams and a LED score test result of about 51 degrees.

Examples 246 and 247 used the media of example 245. An aqueous emulsion of Hystretch V-60 tack agent was sprayed against both sides of the media to provide the add-ons shown in Table 6. Examples 246 and 247 were dried by running through a three zone forced air dryer with zone temperatures of about 280° F., 320° F. and 350° F. Physical properties of these Examples are illustrated on Table 6.

Tackified Nonwoven Filtration Media 6

Examples 248 to 252 were prepared by carding and cross lapping fibers to form a matt. This matt comprises about 80% 4 denier staple length, lower melting point polyester sheath, higher melting point polyester core conjugate fibers and about 20% 3 denier staple length, monocomponent polyester fibers. The fibers are substantially homogeneously distributed throughout the single layer media. One side of the matt was heated over a heated roller to partially melt and fuse the fibers.

Foams were prepared by mixing the reported amounts of tackifier and water. The tackifier and water mixture was wisked forcefully for about 60 seconds to entrain air into the mixture and form a foam. The foam was applied to the media in a uniform fashion using a flat blade applicator.

The aqueous based foam of Hystretch V-60 tack agent was applied to one side of Examples 248 to 252 to provide the add-ons shown in Table 6 in percentage by weight. Examples 248 to 252 were dried for about four hours at a temperature in the range of about 60° F. to about 80° F. Physical properties of these Examples are illustrated on Table 6.

For a nonwoven, self supporting media a minimum basis weight is required to achieve a desired efficiency. A nonwoven, self supporting, non-tackified MERV 6 efficiency filtration media will typically require a basis weight of about 0.4 osf. To increase the efficiency of that media to MERV 8, the basis weight will have to be increased to about 0.6 osf. Surprisingly, if a tackifier is added to a nonwoven, self supporting, MERV 6 efficiency filtration media having a basis weight of about 0.4 osf the resulting tackified filtration media can achieve a MERV 8 efficiency. Further surprisingly, adding a tackifier to a self supporting filtration media appears to increase stiffness of the resulting tackified media. Thus, adding a tackifier to a self supporting media provides surprising increases to efficiency and stiffness without increasing base media weight.

While preferred embodiments of the foregoing invention have been set forth for purposes of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit and scope of the present invention.

TABLE 2 Examples staple fibers 4 denier 2.25 10 denier 3 denier bico fiber 15 denier 0.9 denier denier 3 denier bico fiber 1599 fibers 45 denier chargeable 4 denier Example note 1 polyester polyester polyester polyester note 2 note 3 polyester polypropylene polyester kenaf  1 50% 25% 25%  2 70% 15% 15%  3 70% 15% 15%  4 60% 20% 20%  5 60% 25% 15%  6 80% 20%  7 50% 25% 25%  8 80% 10% 10%  9 80% 20% 10 80% 20% 11 60% 20% 20% 12 70% 15% 15% 13 70% 15% 15% 14 50% 25% 25% 15 50% 25% 25% 16 50% 25% 25% 17 50% 25% 25% 18 50% 25% 25% 19 note 12 70% 15% 20 50% 25% 25% 21 70% 15% 15% 22 50% 25% 25% 23 70% 15% 15% 24 40% 20% 40% 25 60% 25% 15% 26 note 12 70% 30% 27 50% 35% 15% 28 60% 20% 20% 29 70% 15% 15% 30 70% 30% 31 50% 25% 25% 32 60% 15% 25% Thickness Frazier Weight Weight (inches) perm. Gurley - MD Gurley - CD LED dP PFE Example (OSF) (gsm) note 4 (CFM/sq. ft.) (mg) (mg) Score test range note 5 note 6 comments  1 0.56 171 0.07 499 3316 3153 85.8 A 0.106 50.3  2 0.58 177 0.07 321 3266 3155 62.2 A 0.184 57.5  3 0.55 168 0.06 334 3225 2991 72.5 A 0.162 61.5  4 0.54 165 0.08 377 3187 2624 81.7 A 0.141 61.6  5 0.59 180 0.09 353 3056 3064 64 A 0.129 46.7  6 0.57 174 0.07 339 3054 3044 79.7 A 0.168 66.1  7 0.51 156 0.07 432 3038 2495 70.0 A 0.098 46.9  8 0.49 149 0.05 409 2912 2975 90.8 B 0.117 50.2  9 0.54 165 0.09 361 2864 2099 67.3 B 0.133 49.8 10 0.57 174 0.07 331 2855 2943 83.7 B 0.067 30.9 11 0.57 174 0.09 411 2810 2333 60.2 B 0.107 45.5 12 0.57 174 0.11 420 2797 3301 68.7 B 0.134 55.5 13 0.57 174 0.11 420 2797 3301 68.7 B 0.117 54.1 14 0.61 186 0.09 511 2789 1991 66 C 0.089 44.2 15 0.54 165 0.08 491 2786 2339 79.0 C 0.095 48.1 16 0.58 177 0.09 594 2749 2764 58.2 C 0.063 20.9 17 0.59 180 0.11 615 2629 2461 66 C 0.054 35.6 18 0.54 165 0.09 457 2585 2916 64.5 C 0.099 52.2 19 note 12 0.55 168 0.09 532 2583 2634 74 C 0.071 40.8 note 12 20 0.56 171 0.07 340 2520 2949 69.5 C 0.165 61.5 21 0.55 168 0.07 433 2516 2879 69.7 C 0.08 47.8 22 0.66 201 0.11 559 2494 2483 61.3 C 0.07 36.5 23 0.51 156 0.07 349 2485 2694 67.8 C 0.135 60.8 24 0.52 159 0.1 456 2423 1682 61.3 C 0.094 51.9 25 0.53 162 0.06 398 2314 2181 71.5 D 0.13 47.1 26 note 12 0.50 153 0.09 539 2298 2113 86.7 D 0.07 44.4 note 12 27 0.48 146 0.08 541 2283 2601 62.6 D 0.077 44.8 28 0.57 174 0.08 456 2283 2057 62.3 D 0.103 42.2 29 0.62 189 0.08 288 2209 2054 63.3 D 0.211 66.3 30 0.66 201 0.1 330 2195 1755 53 D 0.161 72.9 31 0.57 174 0.1 379 2183 2259 51.3 D 0.134 62.4 32 0.50 153 0.09 465 2136 1800 58 D 0.119 52.7 staple fibers 4 denier 2.25 10 denier 3 denier bico fiber 15 denier 0.9 denier denier 3 denier bico fiber 1599 fibers 45 denier chargeable 4 denier Example note 1 polyester polyester polyester polyester note 2 note 3 polyester polypropylene polyester kenaf 33 50% 25% 25% 34 note 7  70% 30% 35 30% 35% 35% 36 60% 20% 20% 37 50% 25% 25% 38 52%  5% 43% 39 50% 25% 25% 40 note 8  50% 25% 25% 41 60% 15% 25% 42 50% 25% 25% 43 60% 25% 15% 44 70% 30% 45 70% 15% 15% 46 40% 20% 40% 47 60% 25% 15% 48 60% 15% 25% 49 40% 20% 40% 50 50% 25% 25% 51 60% 10% 30% 52 60% 15% 25% 53 50% 20% 30% 54 50% 25% 25% 55 50% 25% 25% 56 50% 20% 30% 57 70% 15% 15% 58 50% 25% 25% 59 note 12 70% 30% 60 60% 15% 25% 61 40% 35% 25% 62 note 9  50% 25% 25% 63 note 11 60% 15% 25% 64 52% 5% 43% 65 60% 15% 25% Thickness Frazier Weight Weight (inches) perm. Gurley - MD Gurley - CD LED dP PFE Example (OSF) (gsm) note 4 (CFM/sq. ft.) (mg) (mg) Score test range note 5 note 6 comments 33 0.48 146 0.1 477 2117 1697 52.3 D 0.106 59.4 34 note 7  0.76 232 0.11 279 2102 1477 67.3 D 0.196 63.1 note 7 35 0.55 168 0.09 365 2035 1640 60.3 D 0.142 67.5 36 0.40 122 0.07 474 2021 2013 94.7 D 0.094 52.8 37 0.51 156 0.1 595 2020 2098 63.7 D 0.067 39.3 38 0.59 180 0.08 340 2013 1806 40 D 0.165 62.2 39 0.38 116 0.09 778 1998 1695 73.2 D 0.031 28.6 40 note 8  0.74 226 0.12 348 1983 1365 60.3 D 0.12 51.5 note 8 41 0.53 162 0.07 427 1981 1935 63.8 D 0.11 46.1 42 0.42 128 0.07 656 1958 1517 66.3 D 0.056 30.6 43 0.52 159 0.08 447 1946 1926 63 D 0.107 47.4 44 0.56 171 0.1 409 1935 2139 78 D 0.122 53 45 0.53 162 0.09 414 1935 1904 49.5 D 0.139 56.2 46 0.56 171 0.09 309 1839 1394 49.5 D 0.205 60.8 47 0.56 171 0.1 442 1780 1795 41.2 0.099 49.3 48 0.44 134 0.06 490 1776 1734 55.5 E 49 0.46 140 0.09 538 1776 1753 84.3 E 0.07 50.0 50 0.43 131 0.07 579 1772 1909 85.2 E 0.076 44.1 51 0.60 183 0.09 348 1761 1611 67.2 E 0.216 64.6 52 0.51 156 0.09 462 1757 1736 59 E 0.108 50 53 0.54 165 0.07 316 1747 1628 61.3 E 0.179 66.9 54 0.59 180 0.1 466 1718 1689 57.2 E 0.114 49.7 55 0.67 204 0.14 571 1715 1783 68.3 E 0.058 41.2 56 0.53 162 0.08 287 1710 2213 70.3 E 0.194 71.5 57 0.48 146 0.09 429 1710 1602 55.8 E 0.105 58.4 58 0.49 149 0.08 379 1695 1614 57.5 E 0.15 53.6 59 note 12 0.44 134 0.09 512 1671 1537 94 E 0.074 45.4  note 12 60 0.52 159 0.09 456 1660 1653 54.2 E 0.102 46.1 61 0.53 162 0.09 525 1650 2129 64.5 E 0.084 53.8 62 note 9  0.62 189 0.11 412 1577 1170 57.7 E note 9 63 note 11 0.47 143 0.07 492 1572 1313 64.5 E 0.095 42.6 UNC 64 0.48 146 0.11 406 1558 1451 65 0.50 153 0.08 478 1554 1443 53.5 E 0.096 47.4 staple fibers 4 denier 2.25 10 denier 3 denier bico fiber 15 denier 0.9 denier denier 3 denier bico fiber 1599 fibers 45 denier chargeable 4 denier Example note 1 polyester polyester polyester polyester note 2 note 3 polyester polypropylene polyester kenaf 66 80% 10% 10% 67 50% 25% 25% 68 60% 20% 20% 69 30% 35% 35% 70 60% 15% 25% 71 50% 25% 25% 72 note 11 50% 50% 73 60% 20% 20% 74 70% 30% 75 note 11 65% 20% 15% 76 50% 15% 35% 77 note 11 40% 30% 30% 78 50% 25% 25% 79 50% 15% 35% 80 40% 20% 40% 81 55% 50% 10% 82 30% 35% 35% 83 60% 20% 20% 84 40% 20% 40% 85 35% 30% 35% 87 40% 30% 30% 88 52% 5% 43% 89 60% 15% 25% 90 80% 10% 10% 91 50% 35% 15% 92 52% 5% 43% 93 70% 15% 15% 94 60% 25% 15% 95 50% 15% 35% 96 note 10 70% 30% 97 50% 25% 25% 98 40% 20% 40% 99 50% 20% 30% Thickness Frazier Weight Weight (inches) perm. Gurley - MD Gurley - CD LED dP PFE Example (OSF) (gsm) note 4 (CFM/sq. ft.) (mg) (mg) Score test range note 5 note 6 comments 66 0.46 140 0.07 514 1550 1844 74.3 E 0.083 49.1 67 0.53 162 0.09 442 1543 1650 63.7 E 0.106 47.8 68 0.52 159 0.1 504 1539 1576 57.7 E 0.08 41.6 69 0.46 140 0.08 418 1532 1517 60.2 E 0.121 63.5 70 0.48 146 0.08 472 1495 1371 67.3 E 0.098 44 71 0.53 162 0.1 360 1477 1410 51.5 E 0.14 50.2 72 note 11 0.50 153 0.07 405 1453 1298 54.7 E 0.12 61 UNC 73 0.49 149 0.08 521 1441 1424 62.8 E 0.088 48.9 74 0.48 146 0.1 490 1430 1415 45.2 E 0.087 45.4 75 note 11 0.38 116 0.05 418 1411 1581 66.5 E UNC 76 0.71 217 0.1 263 1403 1347 42.5 E 0.241 84.3 77 note 11 0.52 159 0.09 514 1371 1531 50.8 F 0.079 40.7 UNC 78 0.51 156 0.09 387 1354 1252 63.2 F 0.14 50.7 79 0.53 162 0.07 312 1351 1275 43.5 F 0.173 65.2 80 0.56 171 0.1 325 1328 1188 49.2 F 0.152 60.2 81 0.45 137 0.09 488 1322 1299 68 F 0.08 47.4 82 0.51 156 0.09 533 1297 1561 63.5 F 0.078 48.2 83 0.51 156 0.11 519 1266 1140 64.7 F 0.087 52.5 84 0.65 198 0.12 321 1261 1241 45.5 F 0.089 66.3 85 0.38 116 0.06 502 1258 1173 59.5 F 0.1 47.8 87 0.50 153 0.09 464 1258 1270 55.3 F 0.097 48.9 88 0.52 159 0.08 356 1243 1386 45 F 0.156 67.8 89 0.39 119 0.08 569 1228 1314 55.7 F 0.071 39.5 90 0.42 128 0.07 548 1212 1384 67.3 F 0.068 40.9 91 0.37 113 0.08 649 1206 1421 42 F 0.06 31.3 92 0.67 204 0.09 258 1193 1280 44.8 G 0.23 72.7 93 0.35 107 0.06 1188 1232 60.7 G 94 0.47 143 0.1 538 1167 1409 54 G 0.078 40.8 95 0.47 143 0.08 432 1164 1414 60 G 0.106 52.2 96 note 10 0.86 262 0.12 246 1159 1521 60.7 G note 10 97 0.47 143 0.1 475 1147 1105 39.3 G 0.101 50.4 98 0.58 177 0.11 310 1099 995 43.3 G 99 0.40 122 0.06 394 1095 1225 53.3 G 0.137 56.5 staple fibers 4 denier 2.25 10 denier 3 denier bico fiber 15 denier 0.9 denier denier 3 denier bico fiber 1599 fibers 45 denier chargeable 4 denier Example note 1 polyester polyester polyester polyester note 2 note 3 polyester polypropylene polyester kenaf 100 50% 15% 35% 101 70% 30% 102 note 12 70% 30% 103 60% 10% 30% 104 55% 50% 10% 105 note 11 60% 15% 25% 106 50% 25% 25% 107 50% 25% 25% 108 note 11 50% 50% 109 50% 35% 15% 110 50% 15% 35% 111 note 11 40% 30% 30% 112 50% 15% 35% 113 40% 20% 40% 114 52% 5% 43% 115 25% 25% 50% 116 25% 25% 50% 117 note 11 50% 50% 118 note 11 60% 15% 25% 119 note 11 60% 15% 25% 120 note 11 40% 30% 30% 121 note 11 40% 30% 30% 122 note 11 65% 20% 15% Thickness Frazier Weight Weight (inches) perm. Gurley - MD Gurley - CD LED dP PFE Example (OSF) (gsm) note 4 (CFM/sq. ft.) (mg) (mg) Score test range note 5 note 6 comments 100 0.39 119 0.06 394 1069 1007 55 G 0.119 57.1 101 0.42 128 0.09 530 1040 1051 52.5 G 0.079 43.6 102 note 12 0.41 125 0.08 527 1032 1173 too curled G 0.077 43.8 note 12 103 0.38 116 0.06 405 977 944 64.8 G 0.135 49.9 104 0.40 122 0.08 563 960 1041 68.2 G 0.078 38.1 105 note 11 0.37 113 0.07 613 955 1063 65 G UNC 106 0.39 119 0.09 543 874 829 52 G 0.077 49.3 107 0.40 122 0.08 608 866 810 63.2 G 108 note 11 0.40 122 0.06 483 821 722 49 G UNC 109 0.52 159 0.07 229 820 912 49 G 0.246 72 110 0.40 122 0.06 388 803 864 55.3 G 0.139 62.2 111 note 11 0.40 122 0.09 632 637 710 56.7 G UNC 112 0.39 119 0.08 421 622 710 52 G 0.116 60.8 113 0.36 110 0.07 448 577 548 42.7 G 0.114 50 114 0.41 125 0.07 464 522 458 47.8 G 115 0.61 186 0.12 232 328 2422 68.8 G 116 0.56 171 0.1 413 140 798 73.3 G 117 note 11 0 0.119 56.6 CHGD 118 note 11 0 0.083 34.2 CHGD 119 note 11 0 0.057 38.7 CHGD 120 note 11 0 0.089 39.8 CHGD 121 note 11 0 0.056 25.7 CHGD 122 note 11 0 0.136 47.3 CHGD note 1 - this fiber is a 4 denier, high melting point PET core, low melting point PET sheath bicomponent fiber note 2 - this fiber is a 10 denier, high melting point PET core, low melting point PET sheath bicomponent fiber note 3 - this fiber is a polycotton thread shodde or blend of staple length, recycled polyester fibers and cotton fibers note 4 - thickness is measured on a 12 inch square sample subjected to a compression of 2 grams per square inch. note 5 - pressure drop note 6 - particle filter efficiency, ASHRAE 52.2-1999 note 7 - this is a multilayered composite material comprising a 0.5 osy spunbond layer @ 320/a HPR25LB2DPR layer/a polyester bicomponent fiber comprising staple fiber nonwoven layer note 8 - this is a multilayered composite material comprising a spunbond layer/a HP29LG2DPR layer @ 375/a polyester bicomponent fiber comprising staple fiber nonwoven layer note 9 - this is a multilayered composite material comprising a spunbond layer/a HP27LB2DPR layer @ 375/a polyester bicomponent fiber comprising staple fiber nonwoven layer note 10 - this is a multilayered composite material comprising a 0.5 OSY spunbond layer @ 320/a HP29LG2DPR layer/a polyester bicomponent fiber comprising staple fiber nonwoven layer note 11- UNC is uncharged, CHGD is charged note 12 - this is a multilayered composite material comprising a 0.5 osy spunbond layer

TABLE 3 Examples staple fibers 10 den 15 den Thickness 4 den bico bico bico Weight Weight (inches) Example note 1 note 2 note 3 0.9 den 3 den 45 den (OSF) (gsm) note 5 123 55% 10% 50% 0.4 122 0.08 124 35% 35% 30% 0.38 116 0.06 125 55% 10% 50% 0.45 137 0.09 126 25% 50% 25% 0.49 149 0.1 127 50% 30% 20% 0.5 153 0.08 128 10% 65% 25% 0.54 165 0.1 129 50% 30% 20% 0.49 149 0.09 130 25% 50% 25% 0.56 171 0.08 131 25% 50% 25% 0.56 171 0.08 132 25% 50% 25% 0.57 174 0.1 133 35% 35% 30% Frazier perm. MD Gurley - CD Gurley - LED Pleat dP PFE MERV, Example (CFM/sq. ft.) mg mg Score test Memory note 6 note 7 Index est. 123 563 960 1041 68.2 0.078 38.1 488 6 124 502 1258 1173 59.5 0.1 47.8 478 6 125 488 1322 1299 68 0.08 47.4 593 6 126 569 1569 2083 94.5 5.75 0.081 43.2 533 127 466 2598 2609 82 6.25 0.094 55.7 593 128 671 2615 2223 101.5 4 0.033 17.8 539 129 472 3005 2809 94.2 7.38 0.089 51.8 582 130 590 3382 3334 101.7 8.88 0.055 41.1 747 131 546 3498 3683 94.7 6.63 132 561 3574 3584 94.2 9.31 133 note 1 - This fiber is a 4 denier, high melting point PET core, low melting point PET sheath bicomponent fiber. note 2 - This fiber is a 10 denier, high melting point PET core, low melting point PET sheath bicomponent fiber. note 3 - This fiber is a 15 denier, high melting point PET core, low melting point PET sheath bicomponent fiber. note 4 - 15 percent binder resin. note 5 - thickness is measured on a 12 inch square sample subjected to a compression of 2 grams per square inch. note 6 - pressure drop. note 7 - particle filter efficiency, ASHRAE 52.2-1999.

TABLE 4 Examples staple fibers 4 denier 2.25 15 denier 1599 3 denier bico 15 denier 0.9 denier denier 3 denier bico fiber fibers 45 denier chargeable example note 1 polyester polyester polyester polyester note 2 note14 polyester polypropylene 134 60% 20% 20% 135 80% 10% 10% 136 note 11 70% 15% 137 50% 25% 25% 138 50% 35% 15% 139 70% 15% 15% 140 35% 30% 35% 141 60% 30% 10% 142 65% 20% 15% 143 55% 25% 20% 144 55% 25% 20% 145 60% 20% 20% 146 note 13 60% 30% 147 70% 30% 148 70% 20% 10% 149 50% 30% 20% 150 80% 5% 15% 151 80% 5% 15% 152 80% 5% 15% 153 80% 20% 154 60% 30% 10% 155 70% 30% 156 70% 30% 157 70% 30% 158 65% 20% 15% 159 65% 20% 15% 160 60% 15% 25% 161 15% 50% 35% 162 35% 50% 15% 163 35% 50% 15% 164 50% 15% 35% 165 60% 15% 25% 166 60% 15% 25% Frazier 1 to 3 3 to 10 perm micron micron Weight Thickness (CFM/sq. LED dP PFE PFE example (OSF) note 3 ft.) MD Gurley CD Gurley Score test Memory note 4 note 5 note 5 Index MERV 134 0.4 0.08 608 50 0.066 41.6 630 6 135 0.37 0.05 502 93.7 0.094 42 447 6 136 note 11 0.43 0.09 551 1452 1378 75.1 0.067 34.7 518 5 137 0.037 28.6 773 5 138 0.49 0.09 511 1846 2498 66.2 0.083 45.7 551 139 0.36 0.08 599  896 0.061 40 656 6 140 0.41 0.08 498 1517 0.081 28.3 349 5 141 0.53 0.1 500 2326 2335 63 0.072 47.8 664 6 142 0.53 0.1 463 2167 2470 69 0.089 53.1 597 7 143 0.5 0.1 488 1946 2032 61.5 0.08 49.5 619 6 144 0.51 0.1 465 2101 2733 49.3 0.095 50 526 6 145 0.51 0.09 469 1678 2304 0.085 51.6 607 7 146 note 13 0.49 0.08 506 2338 2372 68.7 0.097 56.3 580 7 147 0.52 0.07 523 3005 71 0.075 51.6 688 7 148 0.5 0.09 441 2401 2737 53.3 0.104 55.9 538 7 149 0.48 0.08 488 2241 2303 39.7 0.086 56.1 652 7 150 0.39 0.05 489 1874 1420 69 0.075 43.8 584 6 151 0.44 0.05 425 2690 2435 70 0.094 42.0 447 6 152 0.38 0.06 487 2179 1804 71.7 0.081 47.3 584 6 153 0.38 0.06 468 2265 2125 63.3 154 0.5 0.08 476 2839 2921 85.3 0.099 62.0 626 7 155 0.47 0.09 383 1354 1343 66 0.122 63.0 516 7 156 0.55 0.1 319 1695 1835 58.3 157 0.41 0.09 428 1459 1261 74.8 0.094 52.0 553 7 158 0.53 0.08 428 83.7 159 0.51 0.08 468 2740 2620 87 0.099 63.5 641 7 160 0.49 0.08 514 2173 2106 63.3 0.069 60.5 877 161 0.51 0.11 818 2269 2120 83.7 4.25 0.035 55 1571 162 0.49 0.09 587 1453 1463 70.7 0.062 35.7 576 163 0.46 0.09 615 55.7 5.5 0.059 50.1 849 164 0.52 0.07 528 2992 3009 79.7 5.13 0.083 53.7 647 165 0.49 0.08 498 2302 2134 62 0.078 59.4 762 166 0.51 0.11 509 3301 2473 79.2 0.083 50.1 604 4 denier 2.25 15 denier 1599 3 denier bico 15 denier 0.9 denier denier 3 denier bico fiber fibers 45 denier chargeable example note 1 polyester polyester polyester polyester note 2 note14 polyester polypropylene 167 60% 15% 25% 168 60% 15% 25% 169 note 12 50% 25% 25% 170 15% 50% 35% 171 15% 50% 35% 172 15% 50% 35% 173 15% 50% 35% 174 50% 30% 20% 175 80% 10% 10% 176 80% 10% 10% 177 178 179 180 15% 50% 35% 181 15% 50% 35% 182 15% 50% 35% 183 10% 65% 25% 184 50% 20% 30% 185 45% 40% 15% 186 45% 40% 15% 187 45% 40% 15% 188 65% 15% 15% 189 70% 15% 15% 190 15% 50% 35% 191 20% 50% 30% 192 20% 50% 30% 193 15% 50% 30% 194 35% 50% 15% 195 35% 50% 15% 196 25% 60% 15% 197 70% 10% 198 15% 85% 199 20% 80% 200 50% 15% 35% Frazier 1 to 3 3 to 10 perm micron micron Weight Thickness (CFM/sq. LED dP PFE PFE example (OSF) note 3 ft.) MD Gurley CD Gurley Score test Memory note 4 note 5 note 5 Index MERV 167 0.52 0.15 561 3121 2219 78 0.07 51.4 734 168 0.51 0.18 580 2753 2027 56 0.061 46.2 757 169 note 12 0.49 0.13 496 2300 1709 73 0.075 45.4 605 170 0.54 0.1 669 2005 2321 72 0.052 42.7 821 171 0.58 0.1 620 2074 2547 69.7 8.25 0.078 59.4 762 172 0.56 0.08 615 2276 2216 70.2 11.25 0.064 51.1 798 173 0.43 0.08 708 81.2 0.071 42 592 174 0.51 0.1 549 1047 64.5 0.071 45.1 635 175 0.9 0.06 163 7000 6800 0.083 80.6 971 8 176 0.9 0.06 163 7000 6800 79.7 0.083 78.3 943 8 177 0.32 75.9 237 178 96.7 0.1 83.4 834 179 0.2 78.3 392 180 0.47 0.1 577 1965 1501 94.3 5.25 0.041 30.5 744 181 0.54 0.08 587 3508 3463 96.7 7.79 0.064 43.5 680 182 0.55 0.1 574 2941 2539 104.2 8.13 0.08 40.4 505 183 0.54 0.11 719 2362 2216 82 5.63 0.069 33.7 488 184 0.48 0.1 523 1983 69.5 5.5 0.075 41.7 556 185 0.49 0.1 545 1261 1710 62.8 6.5 0.078 42.9 550 186 0.48 0.1 581 1593 1993 59.3 7.75 0.062 40.1 647 187 0.48 0.1 542 1280 1500 59.8 6.38 0.067 45.1 673 188 0.47 0.09 508 1608 1473 64.2 7.1 0.08 46.7 584 189 0.52 0.07 419 3737 2945 96.2 7.9 0.112 43.2 386 190 0.52 0.11 794 1872 1857 0.031 36.1 1165 191 0.5 0.11 713 1332 1292 0.037 43.1 1165 192 0.5 0.1 573 1499 1354 0.059 48 814 193 0.51 0.1 743 1593 1891 0.043 43.2 1005 194 0.49 0.12 614 1371 72.2 195 0.43 0.08 642 2067 84.8 196 0.52 0.08 600 2047 77.8 0.054 33.1 613 197 0.47 0.08 561 1248 1459 77.2 0.082 47.5 579 198 0.43 0.06 647 2253 1868 105.3 0.065 35.9 552 199 0.48 0.06 627 2519 2448 98.5 0.065 34 523 200 0.46 0.07 512 2237 2193 76.5 0.085 46.6 548 4 denier 2.25 15 denier 1599 3 denier bico 15 denier 0.9 denier denier 3 denier bico fiber fibers 45 denier chargeable example note 1 polyester polyester polyester polyester note 2 note14 polyester polypropylene 201 50% 25% 25% 202 15% 50% 35% 203 204 205 206 note 7 207 208 note 8 209 note 9  210 note 10 211 10% 65% 25% 212 25% 50% 25% 213 25% 50% 25% 214 25% 50% 25% 215 25% 50% 25% 216 50% 20% 30% 217 50% 20% 30% Frazier 1 to 3 3 to 10 perm micron micron Weight Thickness (CFM/sq. LED dP PFE PFE example (OSF) note 3 ft.) MD Gurley CD Gurley Score test Memory note 4 note 5 note 5 Index MERV 201 0.41 0.06 400 1919 1467 75.7 0.116 47.6 410 202 0.37 0.09 957 903 1066 77 203 0.64 0.14 366 1279 912 52 204 0.45 0.11 886 1285 1436 75.3 205 0.67 0.14 467 1428 1712 51.7 206 note 7 0.57 0.08 574 3064 3543 94.7 0.067 35.2 207 0.069 34.8 208 note 8 0.49 0.14 560 481 68.3 0.057 59.2 87.8 10 209 note 9 0.7 0.16 259 492 48.8 0.167 71.4 93.3 11  210 note 10 0.74 0.16 323 559 45.7 0.141 62.9 85.8 10 211 0.54 0.1 671 2615 2223 101.5 4 0.033 17.8 539 212 0.49 0.1 569 1569 2083 94.5 5.75 0.081 43.2 533 213 0.56 0.08 546 3498 3683 94.7 6.63 214 0.57 0.1 561 3574 3584 94.2 9.31 215 0.56 0.08 590 3382 3334 101.7 8.88 0.055 41.1 747 216 0.5 0.08 466 2598 2609 82 6.25 0.094 55.7 593 217 0.49 0.09 472 3005 2809 94.2 7.38 0.089 51.8 582 note 1 - this fiber is a 4 denier, high melting point PET core, low melting point PET sheath bicomponent fiber. note 2 - this fiber is a 15 denier, high melting point PET core, low melting point PET sheath bicomponent fiber. note 3 - thickness is measured on a 12 inch square sample subjected to a compression of 2 gms per square inch. note 4 - pressure drop. note 5 - particle filter efficiency, ASHRAE 52.2-1999. note 6 - UNC is uncharged, CHGD is charged. note 7 - 25% 2.25 denier, high melting point PET core, low melting point PET sheath bicomponent fibers; 50% 15 denier, high melting point PET core, low melting point PET sheath bicomponent fibers; 25% 45 denier fibers. note 8 - 15% 3 denier polyester fibers; 50% 15 denier high melting point PET core, low melting point PET sheath conjugate fibers; 35% 45 denier polyester fibers + 0.12 osy triboelectric fibers. note 9 - 15% 3 denier polyester fibers; 50% 15 denier high melting point PET core, low melting point PET sheath conjugate fibers; 35% 45 denier polyester fibers + 0.06 osy triboelectric fibers. note 10 - 15% 3 denier polyester fibers; 50% 15 denier high melting point PET core, low melting point PET sheath conjugate fibers; 35% 45 denier polyester fibers + 0.07 osy triboelectric fibers. note 11 - this is a multilayered composite material comprising a 0.5 osy spunbond layer. note 12 - this is a multilayered composite material formed from two layers of carded fibers. note 13 - also includes 10% rayon fibers. note 14 - this fiber is a polycotton thread shodde or blend of staple length, recycled polyester fibers and cotton fibers.

TABLE 5 Number heated Web Heated Example rolls Heated on roll temp F. Nip 1 370 2 2 one side 375 open 3 2 one side 375 open 4 375 5 6 2 one side open 7 370 8 2 one side 380 open 9 350 10 2 one side open 11 310 12 2 one side 365 open 13 2 one side 365 open 14 2 one side open 15 370 16 2 one side open 17 2 one side 320 closed 18 2 one side open 19 2 one side 320 closed 20 two sides closed 22 2 one side open 23 345 open 24 375 25 two sides closed 26 335 27 2 one side 395 open 28 2 one side open 29 2 one side 380 open 30 2 one side 400 open 31 375 32 one side 370 open 33 375 34 320 35 370 36 375 37 2 one side open 38 2 one side open 39 375 40 375 41 2 one side 370 open 42 2 one side open 43 one side open 44 350 45 2 one side 375 open 46 2 one side 400 open 47 2 one side open 48 two sides 370 closed 49 375 50 370 51 2 one side open 52 2 one side 395 open 53 2 one side 380 open 54 2 one side open 55 2 one side 320 closed 56 2 one side 380 open 57 2 one side 365 open 58 one side closed 59 2 one side 320 closed 60 2 one side open 62 375 63 2 one side 345-360 open 65 2 one side 370 open 66 2 one side open 67 2 one side open 68 2 one side open 69 370 70 one side 370 closed 71 two sides open 72 2 one side open 73 2 one side open 74 2 one side 395 open 75 2 one side open 76 2 one side open 77 2 one side 345-360 open 78 one side open 79 2 one side 380 open 80 2 one side open 81 2 one side open 83 2 one side open 84 2 one side open 85 2 one side 395 open 87 2 One side 380 open 88 2 one side 397 open 89 2 one side 395 open 90 2 one side 395 open 91 2 one side open 92 2 one side 380 open 93 2 one side 365 open 94 2 one side 395 open 95 2 one side 395 open 96 320 97 2 one side 395 open 98 2 one side open 99 2 one side 380 open 100 2 one side open 101 2 one side 395 open 102 335 103 2 one side open 104 2 one side open 105 2 one side 345-360 open 106 2 one side 395 open 107 2 one side open 108 2 one side open 109 2 one side 395 open 110 2 one side 380 open 111 2 one side 345-360 open 112 2 one side 395 open 113 2 one side open 114 2 one side 397 open 117 2 one side open 118 2 one side open 119 2 one side open 120 2 one side open 121 2 one side open 122 2 one side open 134 2 one side 395 open 135 2 one side open 136 2 one side 320 open 137 2 one side 320 open 138 2 one side open 139 2 one side open 140 2 one side open 141 2 one side 370 open 142 2 one side 370 open 143 2 one side 370 open 144 2 one side 370 open 145 2 one side 350 open 146 2 one side 370 open 147 2 one side 370 open 148 2 one side 370 open 149 2 one side 370 open 150 2 one side 365 open 151 2 one side 355 open 152 2 one side 355 open 153 2 one side 355 open 154 2 one side 360 open 155 2 one side 360 open 156 2 one side 360 open 157 2 one side 350 open 158 2 one side 350 open 159 2 one side 350 open 160 2 one side 320 open 161 2 one side 340 open 162 2 one side 340 open 163 2 one side 360 open 164 2 one side 340 open 165 2 one side 340 open 166 1 one side 340 closed 167 1 one side 340 open 168 1 one side 350 open 169 1 one side 370 open 170 2 one side 350 open 171 2 one side open 172 2 one side 350 open 173 2 one side open 174 2 one side 350 open 175 2 one side open 176 2 one side open 177 2 one side open 178 2 one side open 179 2 one side open 180 1 one side 345 open 181 1 one side 360 open 182 1 one side 360 open 183 1 one side 345 open 184 2 one side open 185 2 one side 340 open 186 2 one side 340 open 187 2 one side open 188 2 one side 340 open 189 2 two sides 310 open 190 2 one side 380 open 191 2 one side 380 open 192 2 one side 380 open 193 2 one side 380 open 194 1 one side 350 open 195 1 one side 375 open 196 2 one side open 197 2 one side 395 open 198 2 one side open 199 2 one side open 200 2 one side 395 open 201 2 one side 395 open 202 2 one side open 203 2 one side open 204 2 one side open 205 2 one side open 206 2 one side open 207 2 one side open 208 2 one side open 209 2 one side open 210 2 one side open 211 1 one side 345 closed 212 1 one side 345 closed 213 two sides 350 closed 214 one side 350 closed 215 two sides 350 closed 216 1 one side 330 closed 217 1 one side 320 closed

TABLE 6 Examples staple fibers Tribo nonwoven 4 den 15 den 15 den 0.9 den 2.25 den 3 den 45 den Tribo mod filtration example bico bico polyester polyester polyester polyester polyester propylene acrylic Layers media 218 63 17 20 1 219 63 17 20 1 220 63 17 20 1 221 63 17 20 1 1 222 63 17 20 1 1 223 63 17 20 1 1 224 63 17 20 1 1 225 63 17 20 1 1 226 63 17 20 1 1 227 63 17 20 1 1 228 63 17 20 1 1 229 63 17 20 1 1 230 63 17 20 1 1 231 63 17 20 1 1 232 50 15 35 2 233 50 15 35 2 234 50 15 35 1 2 235 50 15 35 1 2 236 50 15 35 1 2 237 50 15 35 1 2 238 50 15 35 1 2 tack Frazier material sides perm. 3 to 10 Weight thickness addon tack (CFM/sq. Gurley - LED micron example (gsm) (mm) tack material (%) applied ft.) MD (mg) Score Range dP PFE Index 218 153 2.5 none 0 0 540 2331 57 D 0.063 47.7 757 219 159 2.5 none 0 0 479 2203 69.3 D 0.073 50.5 692 220 159 2.5 none 0 0 468 2945 72 B 0.084 57.1 680 221 162 2.5 V-60 1.4 1 464 2535 67 C 222 153 2.3 V-60 2.5 1 464 2730 64.3 C 223 171 2.8 V-60 11.5 1 510 2834 55 B 0.064 62.2 972 224 162 2.3 V-60 3.3 2 464 2919 66.3 B 225 168 2.5 V-60 5.7 2 473 2903 60 B 0.083 69.1 833 226 183 2.8 V-60 16.2 2 496 3256 66.3 A 0.071 62.6 882 227 183 2.5 V-60 22.6 2 425 2893 67 B 0.092 67.5 734 228 186 2.8 V-60 23.8 2 464 2612 53.3 C 0.084 66.6 793 229 171 2.5 Flexacryl 1625 11.4 2 450 3730 94 A 0.083 67.3 811 230 165 2.3 Spar Cryl 102 7.9 2 431 2930 80.3 B 0.086 66.6 774 231 165 2.3 Spar Cryl 102 7.9 2 431 2930 80.3 B 0.086 66.6 774 232 162 2.3 none 0 0 608 2078 86.3 D 0.056 48.7 870 233 156 2.0 none 0 0 634 1665 71 E 0.046 37.9 824 234 201 2.3 V-60 7.9 1 568 2368 93 D 0.07 59.4 849 235 207 2.3 V-60 12.3 1 561 2819 74.7 B 0.068 57.6 847 236 201 2.3 V-60 4.6 2 569 2205 78 D 0.062 53.1 856 237 198 2.3 V-60 11.7 2 572 2220 80.7 D 0.066 58.8 891 238 177 2.0 V-60 13.0 2 638 1866 83.7 D 0.05 51.8 1036 Tribo nonwoven 4 den 15 den 15 den 0.9 den 2.25 den 3 den 45 den Tribo mod filtration example bico bico polyester polyester polyester polyester polyester propylene acrylic Layers media 239 37.8 11.4 26.5 12.2 12.2 3 240 37.8 11.4 26.5 12.2 12.2 1 3 241 37.8 11.4 26.5 12.2 12.2 1 3 242 37.8 11.4 26.5 12.2 12.2 1 3 243 50 25 25 4 note 2 244 50 25 25 2 4 note 2 245 50 8 43 5 246 50 8 43 1 5 247 50 8 43 1 5 248 80 20 1 6 249 80 20 1 6 250 80 20 1 6 251 80 20 1 6 252 80 20 1 6 tack Frazier material sides perm. 3 to 10 Weight thickness addon tack (CFM/sq. Gurley - LED micron example (gsm) (mm) tack material (%) applied ft.) MD (mg) Score Range dP PFE Index 239 159 2.0 none 0 0 505 1731 65.3 E 0.077 77.9 1012 240 165 2.5 V-60 7.0 2 463 1672 70 E 0.09 68.9 241 180 2.8 Flexacryl 1625 10.0 2 471 2153 97 D 0.87 75.9 242 183 3.0 Spar Cryl 102 5.9 2 475 1569 98.3 E 0.079 70.4 243 149 3.3 none 0 0 496 2300 71.6 D 0.075 45.4 605 244 165 3.6 V-60 6.0 2 434 3099 62.1 A 0.098 62.1 634 245 174 3.0 none 0 0 230 1965 51 D 0.169 88.3 522 246 174 3.0 V-60 5.0 2 230 1965 51 D 0.169 88.3 522 247 204 3.0 V-60 17.5 2 261 2720 94.3 C 0.16 85.4 534 248 V-60 1.8 1 482 2479 63.3 C 249 V-60 2.4 1 458 3345 67 A 250 V-60 3.5 1 509 1753 56.3 E 251 V-60 5.1 1 440 3123 61 A 252 V-60 6.4 1 509 2035 73.7 D note 1 - tack material Tg: V-60, −60° C.; Flexacryl 1625, −48° C.; Spar Cryl 102, −35° C. note 2 - nonwoven material 4 is a 2 layer material 

1. A tackified air filtration media comprising a thermally bonded nonwoven web comprising a generally homogeneous mixture of fiber types, the web comprising about 10% to about 90% by weight of a first type of fibers having a length of about 0.6 cm to about 20 cm, the fibers including a first fiber portion extending substantially continuously along the length of each fiber and comprising a first thermoplastic polymeric material having a first melting point and a second fiber portion extending substantially continuously along the length of each fiber and defining at least a portion of a fiber exterior surface, the second fiber portion comprising a second thermoplastic polymeric material having a second melting point lower than the first melting point, and about 10% to about 90% by weight of a second type of fibers having a length of about 0.6 cm to about 20 cm; the media having a basis weight in the range of about 90 gsm to about 370 gsm; a thickness of about 1.0 mm to about 6.4 mm; a Frazier permeability of about 150 CFM/square foot to about 1000 CFM/square foot; and a combination of MD Gurley stiffness and LED score results selected from one of the following ranges: range Gurley Stiffness (mg) LED score (degrees) A Over 3000 60.2 to 101.7 B 2800 to 3000 55.0 to 104.2 C 2400 to 2800 53.3 to 101.5 D 1800 to 2400 39.7 to 108.2 E 1400 to 1800 41.2 to 98.3  F 1200 to 1400 77.0 to 86.0  G  800 to 1200 39.3 to 68.2  H Under 800 42.7 to 68.8 

and; 0.5 percent by weight of nonwoven web to about 30 percent by weight of nonwoven web of a tackifier on fibers of the air filtration media.
 2. The tackified air filtration media of claim 1, wherein the first thermoplastic polymeric material is polyester.
 3. The tackified air filtration media of claim 1 being a single layer.
 4. The tackified air filtration media of claim 1, wherein the first thermoplastic polymeric material is polyester and the second thermoplastic polymeric material is polyester.
 5. The tackified air filtration media of claim 1, further comprising kenaf fibers having a length of about 0.6 cm to about 20 cm.
 6. The tackified air filtration media of claim 1, comprising about 1.5% to about 15% of the tackifier on fibers of the air filtration media.
 7. The tackified air filtration media of claim 1, wherein one fiber type has a denier in the range of about 0.9 to about 6 and the other fiber type has a denier in the range of about 8 to about
 45. 8. The tackified air filtration media of claim 1, further being a self supporting media.
 9. The tackified air filtration media of claim 1, having a MD Gurley stiffness over
 1700. 10. The tackified air filtration media of claim 1, wherein: the first fiber type is selected from at least one of about 10% to about 85% 4 denier conjugate fibers comprising polyester first and second fiber portions or about 10% to about 85% 15 denier conjugate fibers comprising polyester first and second fiber portions; the second fiber type is selected from at least one of about 5% to about 30% monocomponent polyester fibers having a denier in the range of about 0.9 to about 45; about 15% to about 50% 3 denier chargeable polypropylene fibers; about 15% to about 30% polyester/cotton blend fibers; or about 15% to about 35% cellulosic fibers; at least one fiber type has a denier greater than 10; and about 1.5% to about 6% tackifier.
 11. The tackified air filtration media of claim 1 further comprising a cured, non-fibrous binder resin between the fiber types.
 12. The tackified air filtration media of claim 1 having a combination of Gurley stiffness and LED score results selected from one of the following ranges: range Gurley Stiffness (mg) LED score (degrees) A over 3,000 60.2 to 85.8; B 2,800 to 3,000 60.2 to 90.8; C 2,400 to 2,800 58.2 to 79.0; D 1,800 to 2,400 40.0 to 94.7; E 1,400 to 1,800 42.5 to 94.0; F 1,200 to 1,400 43.3 to 64.8; G   800 to 1,200 39.3 to 63.3; H under 800 42.7 to 68.8.


13. A method of making a tackified air filtration media comprising: forming a fiber mixture, comprising about 10% to about 90% by weight of a first type of fibers having a length of about 0.6 cm to about 20 cm, the fibers including a first fiber portion extending substantially continuously along the length of each fiber and comprising a first thermoplastic polymeric material having a first melting point and a second fiber portion extending substantially continuously along the length of each fiber and defining at least a portion of a fiber exterior surface, the second fiber portion comprising a second thermoplastic polymeric material having a second melting point lower than the first melting point, and about 10% to about 90% by weight of a second type of fibers having a length of about 0.6 cm to about 20 cm; forming the fiber mixture into a nonwoven matt; bonding the fibers in the nonwoven matt, the bonded nonwoven matt having a basis weight in the range of about 90 gsm to about 370 gsm; a thickness of about 1.0 mm to about 6.4 mm; a Frazier permeability of about 150 CFM/square foot to about 1000 CFM/square foot; and a combination of MD Gurley stiffness and LED score results selected from one of the following ranges: range Gurley Stiffness (mg) LED score (degrees) A Over 3000 60.2 to 101.7 B 2800 to 3000 60.2 to 104.2 C 2400 to 2800 53.3 to 101.5 D 1800 to 2400 39.7 to 105.3 E 1400 to 1800 41.2 to 94.5  F 1200 to 1400 42.0 to 86.0  G  800 to 1200 39.3 to 68.2  H Under 800 42.7 to 68.8 

and; applying 0.5 percent by weight of nonwoven web to about 30 percent by weight of nonwoven matt of a tackifier to fibers of the bonded nonwoven matt to form the tackified air filtration media.
 14. The method of claim 13 wherein the step of forming comprises carding the fiber mixture to form the nonwoven matt.
 15. The method of claim 13 wherein the step of forming comprises carding the fiber mixture to form a web and cross lapping the web to form the nonwoven matt.
 16. The method of claim 13 wherein the step of bonding comprises thermal bonding of the fibers in the nonwoven matt.
 17. The method of claim 13 wherein the step of applying comprises spraying a tackifier on a surface of the bonded nonwoven matt.
 18. The method of claim 13 further comprising the step of folding the media to form a self supporting structure.
 19. A non-tackified air filtration media comprising a thermally bonded nonwoven web comprising a generally homogeneous mixture of fiber types, the web comprising about 30% to about 90% by weight of a first type of fibers having a length of about 0.6 cm to about 20 cm, the fibers including a first fiber portion extending substantially continuously along the length of each fiber and comprising a first thermoplastic polymeric material having a first melting point and a second fiber portion extending substantially continuously along the length of each fiber and defining at least a portion of a fiber exterior surface, the second fiber portion comprising a second thermoplastic polymeric material having a second melting point lower than the first melting point, and about 5% to about 70% by weight of a second type of fibers having a length of about 0.6 cm to about 20 cm; the media having a basis weight in the range of about 90 gsm to about 370 gsm; a thickness of about 1.0 mm to about 6.4 mm; a Frazier permeability of about 45,000 LSM to about 260,000 LSM; and a combination of Gurley stiffness and LED score results selected from one of the following ranges: range Gurley Stiffness (mg) LED score (degrees) A Over 3000 60.2 to 101.7 B 2800 to 3000 60.2 to 104.2 C 2400 to 2800 53.3 to 101.5 D 1800 to 2400 39.7 to 105.3 E 1400 to 1800 41.2 to 94.5  F 1200 to 1400 42.0 to 86.0  G  800 to 1200 39.3 to 68.2  H Under 800 42.7 to 68.8 


20. The non-tackified air filtration media of claim 19, wherein one fiber type has a denier less than about 6 and the other fiber type has a denier greater than about
 8. 